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The chemistry of benzotriazole. 10. A conceptually new approach to the synthesis of secondary amides and thioamides | Amides and thioamides of type RC(=X)NHCHR 1 R 2 are prepared in high yield with the formation of a new C-R 2 bond by the action of a Grignard reagent (R 2 MgX) on the readily available adducts from an amide RCONH 2 (or thioamide RCSNH 2 ), aldehyde R 1 CHO, and benzotriazole | Tautomeric structures of 3-amino[1,2,4]triazolo[4,3- a ]pyrimidin-5-one in the gas phase and aqueous solution were investigated using DFT B3LYP/6-311++(2d,2p) calculations. Intramolecular hydrogen bond parameters were calculated and their influence on the stability of the tautomeric forms evaluated using the quantum theory of "atoms in molecules". How to Cite Astakhov, A. V.; Chernyshev, V. M. Chem. Heterocycl. Compd. 2014 , 50 , 319. [ Khim. Geterotsikl. Soedin. 2014 , 349.] For this article in the English edition see DOI 10.1007/s10593-014-1479-2 | eng_Latn | 14,800 |
The reaction of methylborylene with cyclohexene and some other olefinic compounds | Abstract Some potential methylborylene-generating systems were investigated, using cyclohexene as the trapping agent. Methylborylene, generated by the system 2C 8 K/MeBBr 2 , reacts with cyclohexene to yield 2-methyl-2-boratricyclo-[7.4.0.0 3.8 ]-tridecane (MBTT) Ia . In the course of the work an isomer of MBTT was synthesized along a completely different route and compared with Ia . With the system 2C 8 K/MeBBr 2 , only cyclic olefins were converted to analogues of MBTT. An acyclic olefin and a conjugated diene yielded only haloboration products. Possible mechanisms leading to the formation of MBTT Ia are discussed. | We report the solid-phase synthesis and conformational analysis of a 14-membered, cyclic enkephalin analog, HTyrc[DA2buGlyPheDLeu] (where A2bu represents α,γ-diaminobutyric acid). The results from the guinea pig ileum (GPI) and mouse vas deferens (MVD) assays show that the analog, though active, has little selectivity for the μ or δ opioid receptors. Conformational analysis is carried out using 1H-nmr and computer simulations, including molecular dynamics and energy minimizations. The results obtained here are compared with the findings of our studies carried out on the μ-receptor-selective diastereomer, HTyrc[DA2buGlyPheLeu] [N. Mammi, M. Hassan, and M. Goodman (1985) J. Am. Chem. Soc.107, 4008–4013]. This comparison allows for insight into the regiospecificity of these cyclic enkephalin analogs. | eng_Latn | 14,801 |
Synthesis and anti-inflammatory activity of 3,1-benzoxazin-4(3H)-ones and N-acyl-5-iodoanthranilic acid amides | A series of new 3,1-benzoxazin-4(3H)-ones were synthesized and N-acyl-5-iodoanthranilic acid amides derived from them were obtained in a search for new biologically active derivatives of anthranilic acid. The anti-inflammatory activity of these compounds was evaluated. It is established that these classes of compounds are promising for further research on biologically active substances possessing anti-inflammatory activity. | TiCl((OPr)-Pr-i)(3) and NaBH(OAc)(3): an efficient reagent combination for the reductive amination of aldehydes by electron-deficient amines Sodium triacetoxyborohydride, NaBH(OAC)(3) with tri- isopropoxytitanium chloride, TiCl((OPr)-Pr-i)(3) is a useful reagent combination for reductive amination. Electron-deficient amines and heteroaromatic amines such as 2-aminopyrimidine and 2-aminothiazole can be reductively alkylated at room temperature to afford the corresponding secondary amines in good yields. © 2005 Elsevier Ltd. All rights reserved. | eng_Latn | 14,802 |
Bifunctional chiral auxiliaries 5: The synthesis of 1,3-diacylimidazolidine-2-thiones and 1,3-diacylimidazolidin-2-ones from 1,2-diamines☆ | Abstract Although 1,2-diamines fail to cyclise with urea, phosgene or 1,1′-carbonyl di-imidazole, they react with carbon disulphide to give the corresponding imidazolidine-2-thiones. These undergo clean diacylation to give 1,3-diacylimidazolidine-2-thiones which are readily converted to 1,3-diacylimidazolidin-2-ones on treatment with mercury (II) acetate. An alternative two-step route to 1,3-diacylimidazolidin-2-ones uses carbonyl sulphide to effect cyclisation of the 1,2-diamine to the imidazolidin-2-one, which is subsequently diacylated. The ability to convert homochiral 1,2-diamines to homochiral 1,3-diacylimidazolidin-2-ones has also been demonstrated. | AbstractDimethyl 1,1-bis(trimethylsilyl)methylphosphonate and dimethyl 1-(trimethylsilyl)-1-(trimethylstannyl)methylphosphonate were succeeded to react with aromatic aldehydes in the presence of methyl benzoate as additive to give the corresponding vinylphosphonates in moderate yields. | eng_Latn | 14,803 |
Synthesis of the cardiotonic bemarinone, 5,6‐dimethoxy‐4‐methyl‐2(1H)‐quinazolinone, utilizing a directed metalation approach | Several methods for the synthesis of bemarinone, 5,6-dimethoxy-4-methyl-2(1H)-quinazolinone, were explored with the most successful being a directed metalation route. Details of the lithiation and the subsequent reaction with electrophiles of 3′,4′-dimethoxy-2,2-dimethylpropioanilide and other derivatives of 3,4-dimethoxyaniline are given. | Abstract Substituted indoles, carbazoles, benzothiophenes and benzofurans are important motifs in the pharmaceutical industry. Herein we report a novel, regioselective method to introduce alkyl substituents into position ortho of nitro groups by the addition of a Grignard reagent followed by subsequent oxidation with DDQ. | eng_Latn | 14,804 |
Anti-malarial Activity of New Emodin Derivatives against Plasmodium falciparum Chloroquine Resistant Strain | Emodin (1) is the major bioactive compound of several herb species, which belongs to anthraquinone class of compound. As a part of our drug discovery program, large quantities of emodin (1) was isolated from the roots of Rheum emodi and a library of novel emodin derivatives 2–24 were prepared to evaluate their in-vitro antimalarial activity, among them, compound 17, 18 and 20 showed potent antimalarial activity against chloroquine resistant strain PfK1with the IC50 of 2.28, 2.49 and 2.48 μM respectively with a high safety index. | Abstract Asymmetric total synthesis of small ring macrolide stagonolide-E has been described in this communication. The main highlight of our synthetic strategy is the application of ME-DKR (metal enzyme combo dynamic kinetic resolution) reaction, asymmetric reduction with Noyori’s BINAL-H reagent system, stereoselective cross metathesis, and RCM (ring closing metathesis) reaction at a late stage enables us to achieve the synthesis of the target molecule in an efficient way. | eng_Latn | 14,805 |
Solvent-free asymmetric anhydride opening in a ball mill | The mechanochemical technique of ball milling has been applied to the asymmetric opening of meso-anhydrides, mediated by the cinchona alkaloid quinidine. A simple workup procedure affords the products, optically active dicarboxylic acid monoesters, in high yields, with up to 64% ee. With most substrates no column chromatography was needed. A range of various alcohols, as well as anhydrides, reacted well thus demonstrating the scope of this methodology. Even mixtures of purely solid components react, and no solvent is required (except during the workup). The possible use of almost equimolar amounts of starting materials significantly simplifies the product isolation compared to the standard solution reaction. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,806 |
Biaryl ethers as potent allosteric inhibitors of reverse transcriptase and its key mutant viruses: aryl substituted pyrazole as a surrogate for the pyrazolopyridine motif. | Biaryl ethers were recently reported as potent NNRTIs. Herein, we disclose a detailed effort to modify the previously reported compound 1. We have designed and synthesized a series of novel pyrazole derivatives as a surrogate for pyrazolopyridine motif that were potent inhibitors of HIV-1 RT with nanomolar intrinsic activity on the WT and key mutant enzymes and potent antiviral activity in infected cells. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,807 |
New approaches to the synthesis of 2-(trifluoromethyl)indole and 2-amino-3-(trifluoromethyl)quinoline | New synthetic approaches to the preparation of 2-(trifluoromethyl)indole and 2-amino-3-(trifluoromethyl)quinoline have been developed. In both cases, conditions of the Leimgruber-Batcho synthesis of indoles were used in the key step. | The invention discloses a fluoro-substituted triptolide derivative shown as formula (I) or its pharmaceutically acceptable salt or hydrate or their optical isomer, wherein the -- connecting OH and F can represent the following meaning. The invention also discloses a preparation method of the fluoro-substituted triptolide derivative and application of the derivative in medicaments treating cancers and cancer related diseases. | eng_Latn | 14,808 |
Conjugate additions to alkylidene bis(sulfoxides). | A general study on the conjugate addition of anionic nucleophiles to alkylidene bis(sulfoxides) is presented. Alkoxides gave high yielding and diastereoselective addition reactions, which could be influenced by solvents and the counteranion. Azides provided an interesting entry into sulfinyl-substituted triazoles. Organometallics, mainly copper reagents, proved also to be valuable nucleophiles, and complete inversion of the stereoselectivity was achieved in the addition reaction with the latter. Modelizations provide a rationale for the observed diastereoselectivity. | The inhibition of methyltransferases is currently of high interest, particularly in the areas of microbial infection and cell proliferation, as there have been serious attempts to develop novel anti-microbial agents. In the present investigation, a series of 11 S-adenosyl-$L$-homocysteine analogues have been synthesized and effect of these analogues on DNA methylation catalyzed by DNA methyltransferases was studied. It was found that, while $5^{\prime}$-S-(propionic acid)$5^{\prime}$-deoxy-9-($1^{\prime}$-\beta-$D$-ribofuranosyl)1,3-dideazaadenine was an activator of EcoP15I and HhaI DNA methyltransferases, $5^{\prime}$-S-(propionic acid)$5^{\prime}$-deoxy-9-($1^{\prime}$-\beta-dribofuranosyl)adenine inhibited the methyltransferases in a non-competitive manner. An understanding of the binding of analogues to DNA methyltransferases will greatly assist the design of novel anti-microbial compounds. | eng_Latn | 14,809 |
Nitroimidazoles with a halogen-containing side-chain | Syntheses are reported for: nine 2-nitroimidazoles, the abbreviated names all beginning with E, based on derivation from Etanidazole); five 2-methyl-5-nitroimidazoles (M compounds, derived from Metronidazole); and five 2-methyl-4-nitroimidazoles (labelled 2M4N compounds). The nitroimidazoles all have an amide side-chain at the N1 atom of the imidazole, 17 of them containing one to five halogen atoms. The aim is to study compounds for comparison with EF5 (the number showing the presence of five F-atoms), a previously reported, pentafluoropropylacetamide derivative of 2-nitroimidazole that is currently used as a hypoxia marker drug to detect cancerous tumours. The new compounds are characterized by standard methods, including X-ray structural data for the fluorinated MF5, 2M4NF5, and 2M4NF1(-1) species, the ‘-1’ indicating two C-atoms in an alkylamide chain rather than the three C-atoms in the propylacetamide of EF5. Intra- and inter-molecular H-bonding is seen in the solid state structures, likely an impor... | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,810 |
Medium-sized cyclophanes. Part XV. 10,15-Dihydro-5H-tribenzo-[a,d,g]cyclononene and analogues | The preparation of the title compounds based on a novel cycloalkylation reaction of benzene is described. 1H and 13C N.m.r. spectra support the structures. A rigid crown conformation similar to that of cyclotriveratrylene is assigned to carbocycle (IIa) and the sulphur analogues (IId and e). On the other hand, the oxygen analogue (IIc) undergoes a ready inversion between two crown forms, which can be frozen at –90°. Ketone (IIb) is also a flexible molecule. The dependence of structural parameters on the conformational mobility is discussed. The mass spectrum of the sulphone (IIe) reveals ready extrusion of water on electron impact indicating a transannular proximity effect in the nine-membered ring. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,811 |
ChemInform Abstract: Expedient Route to CDE Ring System of Schintrilactones Through Tandem ROM-RCM of a Norbornene Derivative. | A synthesis of the tricyclic ring system (VI)/(VII) includes a key step sequence of ring-opening and ring-closing metathesis of the diastereomeric mixture of (II). | The synthesis of new low-dimensioned solids relies on difficult chemistry that simultaneously takes into account many different factors, some of them largely conflicting. The design of chainlike niobium and tantalum chalcogenides reported here illustrates the experimental approaches that can be used to stabilize chainlike arrangements or to strengthen low-dimensional character when starting from a given compound. | eng_Latn | 14,812 |
An environmentally benign one-pot synthesis of 1,2-dihydro-1-arylnaphtho[1,2-e][1,3]oxazine-3-one derivatives catalysed by phosphomolybdic acid | A phosphomolybdic acid catalysed novel method for the synthesis of 1,2-dihydro-1-aryl-3H-naphth(1,2-e)(1,3)oxazin-3-one derivatives by a one-pot, three-component reaction of β-naphthol, aromatic aldehydes and urea in excel- lent yields is described. | Bromination of O-allylated aldoxime ethers having a trans substituted allyl group with Br(collidine)2PF6 induces an efficient diastereoselective cyclization to give 5-bromooxazine derivatives. | eng_Latn | 14,813 |
Synthesis and characterization of green-emitting phosphorescent Ir(III) complexes based on phenyl benzimidazole ligand | Several new Ir(III) complexes with 2-(4-bromophenyl)-1H-benzo[d]imidazole or 2-(4-bromophenyl)- 1-methyl-benzo[d]imidazole ligands as cylcometalated ligand and acetylacetonate or picolinate as the ancillary ligand were synthesized and their structures and photophysical properties were characterized. HOMO and LUMO energy levels and the molecular structures of Ir(III) complexes were scrutinized by DFT calculations. The complexes exhibited green luminescence at the maximum emission peaks at ca 495–522 nm. The methyl group substituent and replacing of acetylacetonate with picolinate complex can enhance the complex thermal stability. HOMO energy levels of the complexes vary from –4.99 to –5.44 eV, the LUMO energy levels are between –1.52 and –1.97 eV. | Abstract Enantioselective reductions of 2-X-1-(1,3-benzodioxol-5-yl)-1-ethanones, (X = Cl, Br, N 3 ) by Rhodothorula glutinis CCT 2182 afforded the corresponding ( R )-ethanols in good to excellent yields (57–99%) and excellent enantiomeric excesses (>99%). These alcohols may be used as raw materials for the preparation of the pharmaceuticals ( R )-(−)-epinephrine, ( R )-(−)-norepinephrine and ( R )-(−)-isoproterenol. | eng_Latn | 14,814 |
Spectra and structure of 1-aminophthalazines | On the basis of VU and PMR spectroscopic data with the aid of the method of experimental structures and the method of dipole moments it was concluded that the products of the reaction of 1,4-dichlorophthalazine with ammonia, methylamine, and aniline in solutions and in the crystalline form exist primarily as Z conformers of the amino tautomeric form. Conversion to the tautomeric imino form was established for 1-phenylamino-4-chlorophthalazine in a number of solvents. The imines of 2-methyl-4-chlorophthalazine exist as the E isomers. | Abstract In K2ZnCl4 and Rb2ZnCl4, Brillouin scattering of longitudinal acoustic phonons (C11, C22, C33) is performed as a function of temperature around the low temperature structural phase transition at To. Small and different anomalies are observed in both materials. These anomalies are compared to those observed at T3 in Rb2ZnBr4 by Horikx et al. 9 and are tentatively related to the mechanism of the transition. | eng_Latn | 14,815 |
Microwave‐Assisted Solvent‐Dependent Reaction: Chemoselective Synthesis of Quinoxalin‐2(1H)‐ones, Benzo[d]imidazoles and Dipeptides. | Combinatorial syntheses of the title compounds are achieved by microwave-assisted reaction of 10 arylidenephenyloxazolones [e.g. (I)] with 8 ortho-diamines [e.g. (II) and (III)] in various solvents. | Contact immunotherapy is an increasingly used, effective means of treating cutaneous viral warts. Dinitrochlorobenzene, diphencyprone, and squaric acid dibutylester are the most frequently used modalities, showing slight variances in adverse effect profiles and efficacy. All of these agents serve as safe treatment modalities when administered according to the guidelines recommended herein. We review the value of contact immunotherapy in the treatment of cutaneous viral warts. | eng_Latn | 14,816 |
M(co)4[2-(2″-Pyridyl)Benzimidazole] Complexes; m = mo or w | Heating a mixture of M(CO)6, M = Mo or W, and 2-(2′-pyridyl)benzimidazole, PBI, in THF under reduced pressure gave the tetracarbonyl monosubstituted derivative M(CO)4(PBI). Spectroscopic studies showed that these complexes have octahedral structures with two axial and two equatorial carbonyl groups, the PBI ligand occupying two equatorial positions. Electrochemical studies showed reversible and quasi-reversible redox couples due to ligand-based reduction and metal-based oxidation, respectively. | Objective To design and synthesis novel triazole antifungal derivatives and study the antifungal activity.Methods All the target compounds were prepared from 1,3- difluorobenzene via click reaction;The antibacterial activities of the title compounds were determined with broth dilution method.Results Twelve compounds were synthesized and characterized by 1H NMR and MS.All the title compounds exhibited potent antifungal activities against nearly all fungi tested.Conclusion The electronic effects of the substituents affected the activity of compounds,specifically the electron- donating groups. | eng_Latn | 14,817 |
Novel imino rhenium(I) tricarbonyl complexes of salicylidene-derived ligands: Synthesis, X-ray crystallographic studies, spectroscopic characterization and DFT calculations | Abstract Novel rhenium(I) tricarbonyl complexes of the form fac-[Re(L,L′-Bid)(CO)3(S)] (L,L′10.1016/j.poly.2012.08.059-Bid = N,O-Sal-type bidentate ligand, S = coordinating methanol or pyridine) were obtained by the reaction of the fac-[Re(CO)3]+ moiety with a range of 2-(“T”-iminomethyl)-5-methylphenol Schiff-base ligands. Various biological functional groups (“T”) with different electronic and steric properties were introduced at the imino nitrogen atom. The complexes were characterized spectroscopically by IR, 1H and 13C NMR. Three solid state structures were elucidated by X-ray diffraction and compared to DFT calculations employing B3LYP functions in combination with LANL2DZ. | Density functional theory method was employed to study the effect of the nitroamino group as a substituent in cyclopentane and cyclohexane, which usually construct polycyclic or caged nitramines. Based on the optimized molecular structures of two groups of monocyclic nitramines at the B3LYP/6-31G** level, the infrared (IR) spectra were obtained and assigned by harmonic vibrational analysis. The calculated results agree reasonably with the available experimental data. According to the principles of statistic thermodynamics, thermodynamic properties were derived from the IR spectra, which were linearly correlated with the number of nitroamino groups as well as the temperature. The contributions of nitroamino groups to thermodynamic properties are in accord with the group additivity. | eng_Latn | 14,818 |
Controlled trial of azathioprine in children with nephrotic syndrome. A report for the international study of kidney disease in children. | Abstract A prospective, double-blind controlled trial of the therapeutic effect of azathioprine in children with the nephrotic syndrome is reported. Observations were made in 197 children with the nephrotic syndrome, including 38 who did not respond to corticosteroid therapy (" non-responders ") and 49 who did respond but relapsed so frequently that they were considered to be at risk of developing steroid toxicity (" frequent relapsers "). No advantage of azathioprine over placebo was demonstrated in non-responders, and no significant advantage was seen in frequent relapsers. It is concluded that, under the conditions described, azathioprine should not be given to children with the nephrotic syndrome. Of special interest is a group of patients whose renal-biopsy revealed focal glomerular lesions. These patients had severe morbidity and constituted a third of the total group of corticosteroid non-responders. | Structural evolution of the quinqzoline as effective agents in the treatment of microbial infe ctions. Novel quinqzoline based thiosemicarbazide and styryl derivatives have been designed and synthesized. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, 1H NMR. spectral data. All the newly synthesized compounds were screened against various strains of bacterial and fungi.it has been observed that compounds gave significant co-relation. | eng_Latn | 14,819 |
Highly regioselective three-component palladium-catalyzed synthesis of 5-vinyloxazolidin-2-ones from 2,3-allenyl amines, organic iodides, and carbon dioxide | A highly regioselective Pd(0)-catalyzed synthesis of 5-vinyloxazolidin-2-ones from 2,3-allenic amines, organic iodides, and CO2 under mild conditions has been developed. (C) 2013 Elsevier Ltd. All rights reserved. | OBJECT OF THIS PATENT are compounds of formula (I) or salts thereof, where R1, R (squared) are H, an aliphatic saturated or (SUBST.), Phenyl (n.), Or R1 YR (AL SQUARE) together with the nitrogen atom to which they are attached form a heterocyclic OF FORMULA 1 rING, being independently an integer of 1 to 3, R3 is H, an aliphatic saturated or (SUBST.) A REST phenyl, benzyl or phenethyl (n.), OR (squared) and R3 are together form a chain alkylene, R4 is hydrogen, an aliphatic saturated or alkoxy, and R5 is a pyrimidinyl (n.), triazinyl, triazolyl or A REST bicyclic nitrogenous heterocyclene. These compounds have valuable qualities HERBICIDES OR PLANT GROWTH REGULATORS. | eng_Latn | 14,820 |
Association constants of anionic-protactinium (V) complexes | Abstract This study was undertaken to investigate the interaction of aqueous protactinium with various monobasic acids at an ionic strength and acidity of 1·00. This present work adds to the existing information on the anionic complexing of protactinium which was collected at an ionic strength of 3 and an acidity of 1–3 N. The solvent extraction method involves the measurement of the distribution of protactinium (Pa-233) between various aqueous solutions and a benzene phase containing the bidentate chelating agent, thenoyltrifluoroacetone (TTA). | FIELD: chemistry. SUBSTANCE: invention concerns process of production of diisopropyl {[1-(hydroxymethyl)-cyclopropyl]oxy}methylphosphonate represented by the formula , which is the key intermediate compound in synthesis of antiviral nucleoside analogue. The invention also concerns new intermediate compounds of formulae and , and their production of compound (2) obtained under this invention, which is an antiviral nucleoside analogue (especially against hepatitis B virus) represented by the formula . EFFECT: high purity grade and high output. 4 ex | fra_Latn | 14,821 |
Organic amine salt, process for producing same, and process for producing azo dye | An organic amine salt that is a salt of an organic amine represented by formula (A) with an acid represented by formula (B), a process for producing the organic amine salt, and a process for producing an azo dye using the organic amine salt. R 1 , R 2 , R 5 , and R 8 each represent a hydrogen atom or an alkyl, alkenyl, alkynyl, aromatic, or heterocyclic group; R 3 and R 4 each represent a hydrogen atom, an alkyl, alkenyl, alkynyl, aromatic, or heterocyclic group, a halogen atom, an acyl, nitro, or cyano group, or a group represented by formula (C); R 6 and R 7 each represent a hydrogen atom or an alkyl, alkenyl, alkynyl, aromatic, heterocyclic, alkoxy, or hydroxy group; and X represents an oxygen or sulfur atom. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,822 |
The combination of a pyrimidylaminobenzamide and mTOR kinase inhibitor | The present invention, a) a pyrimidylaminobenzamide compound, and b) pharmaceutical combination comprising a mTOR kinase inhibitor, and to provide a method of treating or preventing proliferative diseases using such combinations. | Rotational isomeric state theory provides a relatively simple formalism for the evaluation of the persistence vector, a, for a chain that can be represented by a repeating sequence of independent virtual bonds. The numerical problem can be reduced to the computation of the averages of the elements in the transformation matrices, . This approach is applied for the evaluation of the limiting length of a for poly(benzobisorazole) and poly(benzobisthiazole) as the molecular weight becomes infinite. Some of the elements in can be assigned by symmetry arguments and the remaining nonzero elements are deduced from molecular dynamics theory. | eng_Latn | 14,823 |
Brz220 a novel brassinosteroid biosynthesis inhibitor: stereochemical structure–activity relationship | The four stereoisomers of Brz220 (2RS,4RS-1-[4-propyl-2-(4-trifluoromethylphenyl)-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole), a novel brassinosteroid biosynthesis inhibitor, were separated by silica gel column chromatography and chiral high-performance liquid chromatography (HPLC). The absolute configuration of each stereoisomer was determined by a combination of asymmetric synthesis and NMR analysis. The effects of these stereoisomers on cress stem elongation clearly indicate that the (2S)-isomer has the greatest inhibitory activity. | Rotational isomeric state theory provides a relatively simple formalism for the evaluation of the persistence vector, a, for a chain that can be represented by a repeating sequence of independent virtual bonds. The numerical problem can be reduced to the computation of the averages of the elements in the transformation matrices, . This approach is applied for the evaluation of the limiting length of a for poly(benzobisorazole) and poly(benzobisthiazole) as the molecular weight becomes infinite. Some of the elements in can be assigned by symmetry arguments and the remaining nonzero elements are deduced from molecular dynamics theory. | eng_Latn | 14,824 |
Bis(η2-ethylene)(η5-indenyl)iridium(I) | The asymmetric unit of the title compound, [Ir(C9H7)(C2H4)2], consists of two independent molecules. The bonding between iridium and the five-membered ring of the indenyl ligand shows the usual asymmetry associated with the typical ring slippage responsible for the enhanced activity of indenyl metal compounds when compared with the analogous cyclopentadienyl metal compound. There are three short Ir—C bonds of 2.210 (3), 2.190 (4) and 2.220 (3) A and two long Ir—C bonds to the C atoms that are part of the fused six-membered ring of 2.349 (4) and 2.366 (3) A for one of the independent molecules [2.208 (4), 2.222 (3), 2.197 (4) A for the short distances and 2.371 (3) and 2.358 (3) A for the long distances in the second molecule]. This results in both indenyl ligands being slightly kinked, with dihedral angles of 6.8 (4)° and 6.5 (4)°. | The infrared absorption spectra of urea, thiourea, and thiourea complexes with cesium bromide, potassium iodide, potassium bromide, sodium bromide, and sodium iodide have been observed from 2 to 40 μ, except for the sodium iodide complex which was studied between 2 and 15 μ. The vibrations of urea and thiourea are assigned on the basis of a planar C2v structure. | eng_Latn | 14,825 |
Structural characterization of two oxadiazolic systems used as spacers for potential angiotensin II receptor antagonists | Abstract The structures of two oxadiazole derivatives, methyl 2-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]benzoate (1) and methyl 2-[3-(4-methylphenyl)-1,2,4-oxadiazol-5-yl]benzoate2, used as spacers in the synthesis of new potential non-peptide angiotensin receptor antagonists have been determined by X-ray crystallography. In both compounds π–π interactions were observed between the oxadiazole rings and the phenyl rings of neighboring molecules. In the crystal packing of the oxadiazole 2 two C–H⋯O interactions are present. | Abstract A numerical scheme, based upon the Kobayashi-Tranter method with certain modifications, is given for axisymmetric punch and crack problems in elasticity. The problems are reduced to solving a system of linear algebraic equations instead of a Fredholm integral equation of the second kind. A standard program thus allows the treatment of a range of different cases. The indentation of a rigid punch on an elastic layer overlying an elastic foundation is formulated in this fashion and numerical results for various cases are presented. | eng_Latn | 14,826 |
Photo- and thermochromic spirans. 16. 2-Oxo-3-phenyl-5,5-dimethylspiro(1,3-oxazolidine-4,2′-[2h]chromenes) | New spirans of the 5,5-dimethyl-3-phenyl-2-oxazolidone series that display photo-chromic properties in alcohol solutions at -80 °C were synthesized. The photoinduced forms are characterized by the presence of two long-wave absorption bands at 350–420 nm and 500–650 nm. The 1H and 13C NMR spectra were studied. Anisochronicity of the diastereotopic methyl groups of the oxazolidone ring shows up only in the 13C NMR spectra. | ABSTRACT Several new thienopyridine and methylthioether derivatives have been synthesized. New synthesis of pyrido[2,3-b]-thieno[3,2-d]pyrimidine and penta substituted benzene were achieved. | eng_Latn | 14,827 |
Acid-Catalyzed Synthesis of Thiazolidin-4-ones | ABSTRACTA two-steps synthesis of thiazolidin-4-ones, from α-tetralone 6 or thiochroman-4-one 7, catalyzed by acids is described. The reactions of α-tetralone 6 or thiochroman-4-one 7, with substituted thiosemicarbazides, under AcOH or heteropolyacid (HPAs) catalysis afford thiosemicarbazones 8 and 9 in excellent yields. Condensations of the previous compounds 8 and 9 with α-bromoester, under sulfuric acid or heteropolyacid catalysis, yield the corresponding thiazolidin-4-ones 10 and 11. | TiCl((OPr)-Pr-i)(3) and NaBH(OAc)(3): an efficient reagent combination for the reductive amination of aldehydes by electron-deficient amines Sodium triacetoxyborohydride, NaBH(OAC)(3) with tri- isopropoxytitanium chloride, TiCl((OPr)-Pr-i)(3) is a useful reagent combination for reductive amination. Electron-deficient amines and heteroaromatic amines such as 2-aminopyrimidine and 2-aminothiazole can be reductively alkylated at room temperature to afford the corresponding secondary amines in good yields. © 2005 Elsevier Ltd. All rights reserved. | yue_Hant | 14,828 |
Manually guided botulinum toxin type A submandibular injections for the treatment of sialorrhea in tube-fed patients with advanced amyotrophic lateral sclerosis. | Approximately 50% of patients with amyotrophic lateral sclerosis (ALS) develop sialorrhea and drooling.[1][1] This condition causes soiling and damage of clothing, facial skin maceration, local bacterial infections, and loss of self- esteem and quality of life. Moreover, when it is accompanied by | An efficient one-pot method for the synthesis of tert-butyl 6-aminonicotinate (5) is described. The key transformation involves displacement of the chloro group in tert-butyl 6-chloronicotinate (2) with azide followed by a Staudinger reaction. The scope of this methodology is further extended for the synthesis of a series of carboxylate-substituted heteroaryl amines. In particular, we synthesized tert-butyl carboxylate-substituted amino-pyridine, -pyridazine, and -pyrazine. In addition to one-pot conversion, short reaction time, simplicity of operation, ease of purification, and good yields are the key advantages of this methodology. | eng_Latn | 14,829 |
Reaction of 3-Alkynylquinoxaline-2-carbonitriles with Sodium Azide: an Experimental and Theoretical Study | The reaction of 3-alkynylquinoxaline-2-carbonitriles with sodium azide in DMF at 60 °C leads to the formation of 4,5-disubstituted 2H-1,2,3-triazoles in 38-82% yields. The analogous reaction in toluene in the presence of AlCl3 takes place as a tandem process involving 1,3-dipolar cycloaddition of the azide ion to the nitrile group followed by 6-endo-digonal cyclization with the formation of 5-aryl-tetrazolo[1′,5′:1,3]pyrido[3,4-b]quinoxalines. | For the first time, a quaternary stereocenter in the α-position of an aldehyde is created in an enantiocontrolled pathway (up to 97% e.e.) using a secondary-amine organocatalyst. | eng_Latn | 14,830 |
Bladder instillations with trimethoprim-sulfamethoxazole in the treatment of urinary infection. | 205 paraplegic inpatients with urinary infections were treated with trimethoprim-sulfamethoxazole (TMP-SMZ) bladder instillations (160 mg TMP + 800 mg SMZ daily for 2 consecutive weeks). 89.3% out of | Tautomeric structures of 3-amino[1,2,4]triazolo[4,3- a ]pyrimidin-5-one in the gas phase and aqueous solution were investigated using DFT B3LYP/6-311++(2d,2p) calculations. Intramolecular hydrogen bond parameters were calculated and their influence on the stability of the tautomeric forms evaluated using the quantum theory of "atoms in molecules". How to Cite Astakhov, A. V.; Chernyshev, V. M. Chem. Heterocycl. Compd. 2014 , 50 , 319. [ Khim. Geterotsikl. Soedin. 2014 , 349.] For this article in the English edition see DOI 10.1007/s10593-014-1479-2 | eng_Latn | 14,831 |
Ruthenium and Iron Carbonyl Clusters Catalyzed Reduction of N,N-dimethylbenzamide and N,N-diethyl-(3-methyl)benzamide | One new Ruthenium and one known Iron bimetallic carbonyl clusters containing triphos (1,1,1-tris(diphenylphosphinomethyl)ethane) ligand have been prepared as catalyst to study the reduction of amide to amine. All clusters were characterized by elemental analysis, 1HNMR, 31PNMR and IR spectroscopy. The reduction of N,N-dimethylbenzamide and N,N-diethyl-(3-methyl) benzamide catalyzed by Ru and Fe carbonyl clusters were investigated at 100 ~ 110 °C for 24 ~ 28h, polymethylhydrogensiloxane (PMHS) as reduction agent. The products were analysized using GC-MS, IR and UV-vis spectroscopy and an excellent yield (97%) of N,N-diethyl- (3-methyl)benzamine was obtained when using 3 mol% of bimetallic ruthenium carbonyl cluster as catalyst. The data of IR and UV-vis show that the frameworks of clusters are not changed remarkably during the reaction. | TiCl((OPr)-Pr-i)(3) and NaBH(OAc)(3): an efficient reagent combination for the reductive amination of aldehydes by electron-deficient amines Sodium triacetoxyborohydride, NaBH(OAC)(3) with tri- isopropoxytitanium chloride, TiCl((OPr)-Pr-i)(3) is a useful reagent combination for reductive amination. Electron-deficient amines and heteroaromatic amines such as 2-aminopyrimidine and 2-aminothiazole can be reductively alkylated at room temperature to afford the corresponding secondary amines in good yields. © 2005 Elsevier Ltd. All rights reserved. | eng_Latn | 14,832 |
The Chemistry of Unsubstituted Mono- and Di-amidrazones | The literature data on the methods of preparation and the reactions of unsubstituted mono- and di-amidrazones are discussed. Particular attention has been devoted to the employment of di-amidrazones in the synthesis of heterochain polymers. The bibliography includes 111 references. | Use: in medicine as an antiallergic agent. SUMMARY OF THE INVENTION: 2-derivatives of formula aminopirimi- dinonyl TTA VN NR 6 N-L 3 wherein L - AI Az - Az - A4 - bivalent radical of formula -CH CH-CH-CH-; -N CH-CH-CH-; -CH CH-CH-N -; n 0; 1 and 2: In the group NH, CH2, O or S. Reagent 1: Compound formulyR, i N Al. N Ch-1 VCHK V (CH, CN A Reagent 2: compound of formula:. Rs-vV5 N- / WK-W, & amp; deg; The reaction conditions are: a reaction-inert solvent, base Table 4.. | eng_Latn | 14,833 |
Tachykinin receptor antagonists as 1- (1,2-disubstituted piperidinyl) -4-substituted piperidine derivatives | (57) Abstract: The present invention, as substance P antagonists, compounds of formula (I), these N- oxide forms, For these pharmaceutically may receive addition salts and their stereochemically isomeric forms in the above formula, n is 0, 1 or 2, m is 1 or 2, when m is 2, n is 1, p is 0, 1 or 2, = Q is = O or = NR Le is Het or HetC Kiruokishi, a C | Three crystal forms of the repressor protein TetR class D in complex with the palindromic 17 bp operator sequence containing T overhangs on both sides were obtained by hanging-drop vapor-diffusion methods using PEG 4000 and PEG monomethylether 5000 as precipitants. Although the crystallization conditions were very similar, up to three different crystal forms were observed in the same drop. The space groups are monoclinic C2, P21 and hexagonal P6122. The asymmetric units of the latter two crystal forms contain one repressor-operator complex. The crystal structures of these forms were solved by molecular replacement using the Tet-repressor molecule of the complex with tetracycline as a search model. | eng_Latn | 14,834 |
Benzimidazolium hydrogen nitroterephthalate | In the title compound, C7H7N2+·C8H4NO6−, the partially overlapped arrangement and the shorter face-to-face distance of 3.457 (4) A indicate π–π stacking between parallel benzimidazolium cations, whereas the longer face-to-face distance of 3.649 (6) A suggests normal van der Waals contacts between parallel benzene rings of neighbouring nitroterephthalate anions. | FIELD: chemistry. SUBSTANCE: invention concerns process of production of diisopropyl {[1-(hydroxymethyl)-cyclopropyl]oxy}methylphosphonate represented by the formula , which is the key intermediate compound in synthesis of antiviral nucleoside analogue. The invention also concerns new intermediate compounds of formulae and , and their production of compound (2) obtained under this invention, which is an antiviral nucleoside analogue (especially against hepatitis B virus) represented by the formula . EFFECT: high purity grade and high output. 4 ex | eng_Latn | 14,835 |
Iodine‐Mediated Synthesis of 2‐Arylbenzoxazoles, 2‐Arylbenzimidazoles, and 1,3,5‐Trisubstituted Pyrazoles | Abstract 2‐Arylbenzoxazoles and 2‐arylbenzimidazoles were synthesized by the reaction of aldehydes with 2‐aminophenol and O‐phenylenediamines in the presence of iodine. 1,3,5‐Trisubstituted pyrazoles were synthesized from chalcones and hydrazines in the presence of iodine. CDRI Communication No. 6509. | Rotational isomeric state theory provides a relatively simple formalism for the evaluation of the persistence vector, a, for a chain that can be represented by a repeating sequence of independent virtual bonds. The numerical problem can be reduced to the computation of the averages of the elements in the transformation matrices, . This approach is applied for the evaluation of the limiting length of a for poly(benzobisorazole) and poly(benzobisthiazole) as the molecular weight becomes infinite. Some of the elements in can be assigned by symmetry arguments and the remaining nonzero elements are deduced from molecular dynamics theory. | eng_Latn | 14,836 |
[Antibacterial activity of a carbenicillin-cephaloridin combination]. | The effectiveness of the combination of carbenicilline and cephaloridine in the ratio of 4:1 was studied. The antibacterial activity of the association whether in vitro or in vivo is sinergic, that is, superior to the simply addition by the individual components. The hematic levels of the combination remain high up to 5 hours after the administration and are greater than those obtained with carbenicilline alone. Levels in the urine are high, therefore the species judged to be resistent in vitro may become sensitive. | A scarce NN=C…π interaction, which plays an essential role in defining the crystal packing patterns, has been found widespread in benzaldehyde (cyanoacetyl)hydrazones, and is rationalized by density functional theory calculations. Molecular electrostatic potential analyses offer an effective further support for the interaction. | eng_Latn | 14,837 |
Double Group Transfer Reactions of an Unsaturated Tantalum Methylidene Complex with Pyridine N-Oxides | The electrophilic nature of the benzamidinate tantalum methylidene complex [TolC(NSiMe3)2]2Ta(CH2)CH3 (1) allows for reactivity with pyridine N-oxides, which leads to the formation of the tantalum oxo complex [TolC(NSiMe3)2]2Ta(O)CH3 (5) and methylpyridines; treatment of 1 with the related nitrone species N-tert-butyl-α-phenylnitrone leads to overall different products. Mechanistic studies show the reactions proceed via regioselective methylene group transfer to the pyridine N-oxides. | A series of homo and heterocyclic alkanoates were prepared and evaluated as insect attractants toward Blattella germanica (L.) and Supella longipalpa (F.). Among these compounds, the tetrahydrofurfuryl alkanoates and 4-tetrahydropyranyl hexanoate showed relatively better activity. It was also observed that, in general, the five-membered compounds were better performers than their sixmembered counterparts. The introduction of an oxygen atom in the ring enhanced the activity, irrespective of the ring size. | eng_Latn | 14,838 |
Synthesis and structural, spectroscopic, and electrochemical characterization of new ruthenium dimethyl sulfoxide nitrosyls | The reactivity of ruthenium(II)− and ruthenium(III)−chloride−dimethyl sulfoxide precursors and of the antimetasatic drug [ImH][trans-RuCl4(dmso-S)(Im)] (NAMI-A, Im = imidazole, dmso = dimethyl sulfoxide) toward NO was investigated. Treatment of [(dmso)2H][trans-RuCl4(dmso-S)2] and mer-RuCl3(dmso)3 with gaseous NO yielded [(dmso)2H][trans-RuCl4(dmso-O)(NO)] (1) and mer,cis-RuCl3(dmso-O)2(NO) (2), respectively. Thus, coordination of the strong π-acceptor NO induces a S to O linkage isomerization of the dmso trans to it to avoid competition for π-electrons. In light-protected nitromethane solutions, complex 2 equilibrates slowly with the two isomers mer-RuCl3(dmso-S)(dmso-O)(NO) (3), with NO trans to Cl, and mer-RuCl3(dmso-S)(dmso-O)(NO) (4), with NO trans to dmso-O; the equilibrium mixture consists of ca. 64% 2, 3% 3, and 33% 4. Treatment of the Ru(II) precursor trans-RuCl2(dmso-S)4 with gaseous NO in CH2Cl2 solution yielded the nitrosyl−nitro derivative trans,cis,cis-RuCl2(dmso-O)2(NO)(NO2) (5). Finally, [... | Abstract Enantioselective reductions of 2-X-1-(1,3-benzodioxol-5-yl)-1-ethanones, (X = Cl, Br, N 3 ) by Rhodothorula glutinis CCT 2182 afforded the corresponding ( R )-ethanols in good to excellent yields (57–99%) and excellent enantiomeric excesses (>99%). These alcohols may be used as raw materials for the preparation of the pharmaceuticals ( R )-(−)-epinephrine, ( R )-(−)-norepinephrine and ( R )-(−)-isoproterenol. | eng_Latn | 14,839 |
Method of obtaining 1, 1,1-trifluoro-2, 3-dichloropropane | FIELD: chemistry. SUBSTANCE: invention relates to method of obtaining 1,1,1-trifluoro-2,3-dichloropropane (243db), which includes contact of 3,3,3-trifluoropropene (1243zf) with chlorine in presence of catalyst, including activated coal, aluminium oxide and/or transition metal oxide. EFFECT: method is clean and efficient. 75 cl, 7 ex, 5 tbl | The invention discloses a fluoro-substituted triptolide derivative shown as formula (I) or its pharmaceutically acceptable salt or hydrate or their optical isomer, wherein the -- connecting OH and F can represent the following meaning. The invention also discloses a preparation method of the fluoro-substituted triptolide derivative and application of the derivative in medicaments treating cancers and cancer related diseases. | eng_Latn | 14,840 |
Synthesis, Self-association, and Anion Recognition of Conjugated Macrocycles Composed of Carbazole and Triazolium Moieties | Conjugated macrocycles 1·BF4 and 1·PF6 composed of carbazole and triazolium moieties were successfully synthesized. These macrocycles effectively self-associate through π–π stacking interactions in solution. They complex with halide ions in the cavity through C–H⋯X− hydrogen bonds, and intriguingly exhibit higher affinity for I− than for Cl− and Br−. The self-association and complexation ability with halide ions of macrocycles 1·BF4 and 1·PF6 are significantly enhanced compared to macrocycle 2 composed of carbazole and triazole moieties. | The reaction of O-(2,4-dinitrophenyl) cyclopentanone oxime with four primary alkylamines and a secondary arylamine, pyrrolidine, in benzene has been investigated. In pyrrolidinolysis, a third order dependence on [amine] has been observed, which has been explained on the basis of a cyclic transition state. The aminolysis with primary alkyl amines shows a normal dependence of second order on [amine]. | eng_Latn | 14,841 |
6-Hydroxydopamine inhibits some effects of mescaline centrally administered to rabbits | The narcotic antagonist naloxone does not antagnonize antinociception elicited in the rabbit by 100 μg/kg of mescaline centrally administered, whereas pretreatment with 6-hydroxydopamine (6-OHDA) inhibits this mescaline effect. Stereotyped behavior of rabbits following central mescaline administration is also prevented by 6-OHDA pretreatment. Since 6-OHDA in known to produce a degeneration of catecholamine containing nerve terminals, a crucial role of catecholamines is suggested in the complex of effects seen in the rabbit after central administration of the hallucinogen. | A unique strategy that helps facilitate macrocyclization has been developed and utilized in the synthesis of a cyclic hexadepsipeptide natural product. By using dehydrophenylalanine amino acids in the synthesis of beauvericin, the precursor to the macrocycle is folded in such a way that the C- and the N- termini of the depsipeptide are closer together and cyclization is facilitated. Two strategies towards construction of the macrocycle have been investigated: (1) a cyclotrimerization approach which utilizes a monomeric dipeptide oxazolone and (2) a linear approach which cyclizes a hexadepsipeptide oxazolone. The macrocycle then underwent a global N-methylation followed by rhodium-catalyzed asymmetric hydrogenation which reduced the unsaturated amino acid residues to their desired saturated forms to give rise to the natural product. With the cyclotrimerization route, beauvericin was afforded in 10% yield over 8 steps, and with the linear route, beauvericin was afforded in 19% yield over 12 steps. | eng_Latn | 14,842 |
Synthesis and Structure of A Carboxyl-Bridged Heteronuclear Copper-Terbium Complex: [CuTb(CH2C(CH3)COO)5(PHEN)(H2O)]2 | The title complex has prepared by the reaction of TbL3, Cu(NO3)2 and phen in H2O/EtOH (where L= f -methylacrylato; phen = 1,10-phenanthroline) and its structure determined by X-ray diffraction methods. The complex crystallizes in the triclinic space group PI with Z = 1, a = 11.569(2), b = 14.584(3), c = 11.479(2) A, f = 101.03(2), g = 104.37(2), n = 74.01(1)°, and the structure was refined to R = 0.041 for 6463 observed reflections. The structure contains a discrete tetranuclear CuTbTbCu molecule. Copper(II) and terbium(III) are bridged by three bidentate carboxyl groups with a Tb ··· Cu separation of 3.9059(9) A. The Tb ion is eight coordinate and exhibits a distorted square antiprism. The Cu ion is five coordinate and has distorted pyramidal geometry. | Thioxo-thioenol tautomerism was discussed in ethyl β-mercaptothiocinnamate and β-mercaptocinnamamides, in connection with their chelating abilities, through the ultraviolet absorption spectra in various solvents, and the estimation of the thioenol by the iodometry. Ethylβ-mercaptothiocinnamate and N-phenyl-β-mercaptocinnamamide were confirmed to be present mainly as the cis-thioenol form, and the equilibrium should be considered only between th thioxo and the cis-thioenol forms. On the contrary, in N-ethyl-β-mercaptocinnamamide, the trans-thioenol form should be taken into consideration in its thioxothioenol tautomerism. | kor_Hang | 14,843 |
Microwave‐assisted Synthesis of 6‐{(5‐Aryl‐1,3,4‐oxadiazol‐2‐yl)methyl}‐6H‐indolo[2,3‐b]quinoxalines | An efficient and convenient synthesis of a new series of 2-{(6H-indolo[2,3-b]quinoxalin-6-yl)methyl}-5-aryl-1,3,4-oxadiazoles from readily available 1,2-diaminobenzene and isatins under microwave irradiation conditions was disclosed. The 6-{(5-aryl-1,3,4-oxadiazol-2-yl)methyl}-6H-indolo[2,3-b]quinoxalines were also prepared by the thermal cyclo-condensation reaction of 2-(6H-indolo[2,3-b]quinoxalin-6-yl)acetohydrazides with carboxylic acids in refluxing POCl3. The microwave-assisted synthesis was rapid and resulted in higher yield of the products at lower operating temperature with reduced waste generation in comparison with the thermal reaction protocol. | The invention discloses a method for preparing Zyprexa crystal form II. The method for preparing the Zyprexa crystal form II comprises the following steps of: dissolving a Zyprexa crude product into acetonitrile; cooling and crystallizing; washing the obtained crystal with ethyl acetate or methylbenzene; and drying to obtain the Zyprexa crystal form II. Compared with the prior art, the method has the advantages of effectively controlling residual quantity of the solvent acetonitrile and contributing to market competition, along with high purity in products. | eng_Latn | 14,844 |
The one-pot three component synthesis of imidazole derivatives by using of 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide as a novel and efficient nanocatalyst | The preparation, characterization and catalytic application of a novel 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide is described. The catalyst was characterized by nitrogen adsorption-desorption analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The thermal stability of the material was also determined by thermal gravimetric analysis (TGA). The catalytic application of 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide nanocatalyst was then investigated in the synthesis imidazole derivatives from benzil, different aldehydes and ammonium acetate under solvent-free conditions in short reaction times and good to excellent yields. ::: The significant advantages of this procedure are low loading of the catalyst, avoiding the use of toxic transition metals, short reaction times, high to excellent yields, easy separation and purification of the products and reusability of this nanocatalyst. | Abstract : Our 1978 review of the tin structural literature reveals many examples of axially-most electronegative, trigonal bipyramidal triorganotin moieties in associated polymer chains, but the structure of trimethyltin azide is unique in consisting of SnC3 moieties in alternating (CH3) 3 Sn(delta +) cationic and N3(CH3)3SnN3 (delta -) aniotic environments in a one-dimensional array with the tin atoms bridged at unequal distances by the alpha-nitrogen atoms of the azide group at which site the chains are bent. (Author) | eng_Latn | 14,845 |
Studies on Pyridine Derivatives(X):Synthesis and Herbicidal Activity of 2-sec-Butylamino-5-(2-aryloylpyrid-4-yl)-1,3,4-thiodiazoles | 2-sec-Butylamino-5-(2-chloropyrid-4-yl)-1,3,4-thiodiazole(BCPT) is a herbicidal leading compound.In order to improve its herbicidal activity and study the relationship between chemical structure and bioactivity,an aryl ether moiety was introduced to the sketch and a new series of compounds were synthesized and the structures were confirmed by 1H NMR and elementary analysis.Preliminary bioassay showed that all the synthesized compounds just showed a poor inhibition rate(0~45%) at 500 mg/L,much weaker than (BCPT)(72%~87%).The result suggested that chloro-atom on 2-position of pyridine ring may be indispensable for herbicidal activity. | Abstract The anomalous temperature dependence of the sign of the spontaneous polarization in a biphenyl ester series of ferroelectric liquid crystals is reported. The reversal of the sign of the spontaneous polarization in the chiral smectic C phase of 2MBNCBC ((S)-2′-methylbutyl-4′-n- nonylcarbonyloxy-(l,l′-biphenyl)-l-carboxylate) is observed at T m. This anomaly is studied in detail as functions of the length of the terminal alkyl chain, the applied electric field, the frequency and the applied hydrostatic pressure. T m has been confirmed to depend on the length of the terminal chain and the applied pressure. However, it is independent of the applied field and the measuring frequency. In the mixture of these compounds, this anomaly is also observed. | yue_Hant | 14,846 |
Rearrangement of unactivated N-alkyl-O-benzoyl hydroxamic acid derivatives with phosphazene bases | Abstract The phosphazene super bases BTPP 5 , P-2- t Bu 6 , and P-4- t Bu 7 mediate the rearrangement of unactivated N -alkyl- O -benzoyl hydroxamic acid derivatives 8 , 11a – f , 13 and 16 to give 2-benzoyloxy amides 9 , 12a – f , 14 and 17 . The rate of reaction was found to be dependant upon the steric nature of the N -alkyl substituent. | FIELD: chemistry. SUBSTANCE: invention concerns process of production of diisopropyl {[1-(hydroxymethyl)-cyclopropyl]oxy}methylphosphonate represented by the formula , which is the key intermediate compound in synthesis of antiviral nucleoside analogue. The invention also concerns new intermediate compounds of formulae and , and their production of compound (2) obtained under this invention, which is an antiviral nucleoside analogue (especially against hepatitis B virus) represented by the formula . EFFECT: high purity grade and high output. 4 ex | eng_Latn | 14,847 |
Studies with polyfunctionally substituted heteroaromatics: 2‐Phenyl‐4‐p‐tolylhydrazono‐2‐oxazoline‐5‐one as a precursor for the synthesis of substituted 1,2,4‐triazoles and pyridines | 2-Phenyl-4-p-tolylhydrazono-2-oxazoline-5-one (3) was rearranged by the action of phenols and naphthols into 1,2,4-triazole-5-carboxylic esters (5) that were rearranged further on reflux in AcOH-ZnCl2 into triazolyl ketones (7). Rearrangement of 3 into 1,2,4-triazole derivatives could also be effected by the action of heterocyclic amines and 1-naphthylamine. © John Wiley & Sons, Inc. | Palladium(II) complexes containing phosphorus and nitrogen donor atoms (iminophosphine), dichlorido{N-[2-(diphenylphosphino)benzylidene]-2-trifluoromethylaniline}palladium(II) 1, dichlorido{N-[2-(diphenylphosphino)benzylidene]-3-trifluoromethylaniline}palladium(II) 2, dichlorido{N-[2-(diphenylphosphino)benzylidene]-2-methylaniline}palladium(II) 3, dichlorido{N-[2-(diphenylphosphino)benzylidene]-3-methylaniline}palladium(II) 4 have been successfully synthesized and fully characterized by FT-IR and NMR (1H, 31P, 19F, and 13C) spectroscopy techniques. These complexes were first step tested in the reaction of bromobenzene and styrene to determine the optimal coupling reaction conditions and then successfully applied as catalysts for Heck cross-coupling reactions of activated and deactivated aryl bromides with styrene derivatives and several acrylates. Copyright © 2014 John Wiley & Sons, Ltd. | eng_Latn | 14,848 |
Zeeman laser interferometry for detection and chemical analysis | Zeeman interferometry has a number of applications for ultrasensitive detection and chemical analysis, including refractive index detection, micro-thermometry, thermooptic spectroscopy, and light scattering. | A highly diastereo- and enantioselective four-component reaction of a diazo ketone with two molecules of anilines and ethyl glyoxylate was achieved under Rh2(OAc)4 and chiral phosphoric acid cocatalyzed conditions. This transformation proceeds through a Mannich-type trapping of the ammonium ylide generated from metal carbene and one molecule of aniline with iminoester derived from another molecule of aniline and ethyl glyoxylate. With this method, a series of chiral α,β-diamino acid derivatives were efficiently constructed in good yields and with good to excellent diastereo- and enantioselectivities. | eng_Latn | 14,849 |
Combination therapy of lower urinary tract disorders using α2δ ligand and NSAID | The invention relates to a method of treating at least one symptom of lower urinary tract disease in a subject in need of treatment comprising administering to said subject a combination of an alpha 2 delta calcium channel subunit (A2d) ligand and a non-steroidal anti-inflammatory drug (NSAID), wherein the administered amounts of A2d ligand and NSAID together comprise a therapeutically effective amount of an active combination of agents. The combination of A2d ligand and NSAID can result in a synergistic therapeutic effect, wherein the combined effect is greater than the additive effect resulting from separate, single administration of A2d ligand or NSAID. Combination of A2d ligand and NSAID is particularly useful in treatment of lower urinary tract disease which manifests symptoms of urinary incontinence. | A scarce NN=C…π interaction, which plays an essential role in defining the crystal packing patterns, has been found widespread in benzaldehyde (cyanoacetyl)hydrazones, and is rationalized by density functional theory calculations. Molecular electrostatic potential analyses offer an effective further support for the interaction. | eng_Latn | 14,850 |
Synthesis and molecular docking studies of novel 2-phenyl-4-{4-[(1-phenyl-1H-1,2,3-triazol-4-yl)methoxy]benzylidene}oxazol-5(4H)-one derivatives | 2-Phenyl-4-{4-[(1-phenyl-1H-1,2,3-triazol-4-yl)methoxy]benzylidene}oxazol-5(4H)-one derivatives were synthesized by click chemistry reactions. Exploration of molecular interaction of the obtained compounds, performed through molecular docking studies with α-glucosidase, revealed the high docking scores (LibDock) in the range of 135.056–126.164 as compared to acarbose (136.345). | A short synthetic route to diastereoisomeric atropos dihydro-5H-dibenz[c,e]azepinium salts via reaction of a single enantiomer of (R)-α-methylbenzylamine with a racemic atropos biphenol derivative is described. Compounds prepared via this approach are used to provide strong evidence that structurally related tropos dihydro-5H-dibenz[c,e]azepinium salts preferentially react via a single conformation in PTC reactions involving glycine imine enolates. | eng_Latn | 14,851 |
An unexpected synthesis of 3,5-diaryl-1,2,4-thiadiazoles from thiobenzamides and methyl bromocyanoacetate. | Aryl thioamides undergo a very rapid condensation in the presence of methyl bromocyanoacetate to provide quantitative yields of 3,5-diaryl-1,2,4-thiadiazoles with easy work-up and a high degree of product purity. The method can be scaled up with no loss in efficiency. | The direct reductive amination of aldehydes using S-benzyl isothiouronium chloride as a recoverable organocatalyst for the activation of the imine intermediate through hydrogen bonding is described. A mild and operationally simple fragment coupling procedure was accomplished with a wide range of aldehydes as well as amines in good to excellent yields. In addition, the S-benzyl isothiouronium chloride catalyst was easily recovered by simple filtration and reused without any drop in its efficiency. | eng_Latn | 14,852 |
Stereocontrolled synthesis of the tricyclic ABC ring system of daphnicyclidin A. | An enantiocontrolled synthesis pathway has been developed to provide formation of tricyclic amine 7, representing the ABC ring system of the complex alkaloid daphnicyclidin A (1). Our efforts describe preparation of the Z-hexahydro-(1H)-azocine 29 and cyclization to construct the novel 4-azabicyclo[5.3.2]dodecane 31. Transannular reductive amination following the deprotection of 31 gave the desired tertiary amine 7. | This paper introduces a new strategy, called "cyclic switching," to deal with the well-known certainty equivalence control synthesis problem which arises in the design of identifier-based adaptive controllers because of the existence of points in parameter space where the design model /spl Sigma//sub D/, upon which certainty equivalence synthesis is based, loses stabilizability. Unlike most previously suggested methods for handling this problem, the technique proposed here can be employed with or without process excitation. For the technique to work it is not necessary for there to be a mechanism for moving tuned parameters away from values at which /spl Sigma//sub D/ loses stabilizability, and no such mechanism is used. > | eng_Latn | 14,853 |
Study on the New Reaction of Different Enamines with Methyl Phenyldiazoacetate | Enamines were prepared from acetophenone and several secondary amines and examined in the reaction with methyl phenyldiazoacetate catalyzed by copper salts.None of the expected aminocyclopropane product was found after careful examination of the reaction mixture instead of γ-ketoester.A full investigation of the effects of enamines,catalysts,solvents on the reaction was carried out. | We thank Angel Colmenar and Laura Balonga for technical support, the BioBanco VIH (Hospital Gregorio Maranon, Madrid) for providing essential reagents, and Simon Bartlett for English editing. This study was supported by grants from the Spanish Ministry of Economy, Industry and Competitiveness (MEIC; RD12/0042/0023 [FEDER cofunded] and SAF2014-52050R and SAF2017-83229R to A.G.A., SAF2015-64287R and SAF2015-71878-REDT to M.R., RD12/0042/0053 [FEDER cofunded] and SAF2015-64767-R to J.M-G., and SAF2016-79490-R and RD12/0042/0028 [FEDER cofunded] to V.A.) and from La Marato TV3 Foundation. C.C., M.M-A., and L.A-H. were funded by fellowships from the Spanish Ministry of Education, MEIC, and La Caixa-CNIC, respectively. C.R. was funded by a competitive postdoctoral contract grant FPDI-2013-17423 from MEIC. The CNIC is supported by the Spanish MEIC and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505). | eng_Latn | 14,854 |
Regio- and Stereoselective Hydrosilylation of 1,4-Bis(trimethylsilyl)-3-buten-1-ynes. | Four kinds of regio- and stereoisomers of hydrosilylation products of 1,4-bis(trimethylsilyl)-3-buten-1-yne (1) could be independently prepared in over 93% selectivities by proper choice of catalysts and cis and trans geometries of 1. | Structural evolution of the quinqzoline as effective agents in the treatment of microbial infe ctions. Novel quinqzoline based thiosemicarbazide and styryl derivatives have been designed and synthesized. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, 1H NMR. spectral data. All the newly synthesized compounds were screened against various strains of bacterial and fungi.it has been observed that compounds gave significant co-relation. | eng_Latn | 14,855 |
Self-assembly of a polynuclear ribbon: the structure of {[Cu2(CN)2(L)]·MeNO2}∞ [L=4,7-bis(2-cyanoethyl)- 1-thia-4,7-diazacyclononane] | The compound {[Cu2(CN)2(L)]·MeNO2}∞ [L=4,7-bis(2-cyanoethyl)-1-thia-4,7-diazacyclononane] has been prepared by reaction of CuCN with L. The complex shows an unusual CuI–CN one-dimensional polymer capped by macrocyclic ligands. | Review: [recent developments in copper-catalyzed skeletal 2,3-rearrangement reactions of O-propargylic oximes to form four-membered cyclic nitrones, pyridine N-oxides, and amidodienes via N-allenylnitrone intermediates; 32 refs. | eng_Latn | 14,856 |
The vapor phase infrared spectra of cyclohexene and 2,3‐dihydropyran, 50–700 cm−1 | The infrared spectrum from 50 to 700 cm−1 of cyclohexene in the vapor phase is reported and analyzed for the first time in terms of a number of very weak sequences resulting from combinations of various fundamentals with the out‐of‐plane skeletal bending and twisting modes. The spectrum of 2,3‐dihydropyran is reinvestigated with the view of finding corresponding combination sequences not previously reported. By means of an approximate method the barriers to planarity and interconversion are estimated to be, respectively, 5826 and 2571 cm−1 for cyclohexene, and 5371 and 3310 cm−1 for 2,3‐dihydropyran. | In the present investigation a series of some novel synthetic Chalcones (2a-d) and their heterocyclic analogs such as Isoxazolines (3a-d), Pyrimidines (4a-d), Pyrazolines (5a-d), Benzodiazepines (6a-d) and | eng_Latn | 14,857 |
Applications of a monomeric orthopalladate complex containing mixed phosphorus–nitrogen donors in the Heck reaction | Abstract The [Pd{C 6 H 2 (CH 2 CH 2 NH 2 )-(OMe) 2 ,3,4}Br(PPh 3 )] monomeric orthopalladate complex of homoveratrylamine and triphenylphosphine was synthesized and its application in Heck coupling reactions was investigated. This complex had been demonstrated to be more active than the corresponding dimeric catalyst for Heck reactions of aryl iodides, bromides and even chlorides and also arenesulfonyl chlorides. The cross-coupled products were produced in excellent yields using catalytic amounts of [Pd{C 6 H 2 (CH 2 CH 2 NH 2 )-(OMe) 2 ,3,4}Br(PPh 3 )] as a thermally stable and oxygen insensitive complex in NMP at 130 °C. | Abstract : We are interested in studying the muscarinic acetylcholine receptor. Our work will involve molecular modeling of muscarinic agonists and antagonists to determine their bioactive conformations. From the modeled ligands we hope to derive a pharmacophoric pattern common to the ligands. This pharmacophoric pattern will enable a topography of the muscarinic receptor to be derived which will facilitate the design of novel agonists and antagonists. The work will concentrate on the design of new antagonists which could be synthesized and tested by army collaborators. These antagonists we hope will prove to be new antidotes for organophosphate poisons. Keywords: Molecular structure; Molecule molecule interactions; Synthesis (Chemistry); Computer programs. | eng_Latn | 14,858 |
Medicated patch comprising 5-methyl-1-phenyl-2-(1h)-pyridone | Disclosed is a medicated patch comprising 5-methyl-1-phenyl-2-(1H)-pyridone. Specifically disclosed is a medicated patch having a percutaneously absorbable preparation layer. The percutaneously absorbable preparation layer comprises 5-methyl-1-phenyl-2-(1H)-pyridone or a pharmaceutically acceptable salt thereof as an active ingredient, a dissolving agent and an aqueous base material (or a rubber-type base material), wherein the active ingredient is contained in an amount of 0.1 to 30 mass% relative to the total amount of the percutaneously absorbable preparation layer. | Polymeric/oligomeric and macrocyclic (salophen)Ni(II) complexes have been synthesized starting from both an achiral biphenol dialdehyde and an optically active BINOL dialdehyde. It was found that these polysalophens contain nonplanar coordination of Ni(II) units that are paramagnetic. This is different from the previously reported (salophen)Ni(II) complexes which are square planar and diamagnetic. The nonplanar (salophen)Ni(II) units make the new polymeric Ni(II) complexes different from the helical structure proposed for chiral biaryl-based polymers containing square-planar (salophen)Ni(II) units. The copolymerization of the chiral binaphthyl monomer with the achiral biphenyl monomer demonstrates that the chirality of the binaphthyl unit is not propagated along the biphenyl polymer chain. | eng_Latn | 14,859 |
Catalytic Asymmetric Direct Henry Reaction of Ynals: Short Syntheses of (2S,3R)‐(+)‐Xestoaminol C and (‐)‐Codonopsinines. | The first efficient, highly anti-diastereo- and enantioselective direct nitro-aldol reaction of ynals (II), (XII) with simple nitroalkanes is presented. | In the present investigation a series of some novel synthetic Chalcones (2a-d) and their heterocyclic analogs such as Isoxazolines (3a-d), Pyrimidines (4a-d), Pyrazolines (5a-d), Benzodiazepines (6a-d) and | eng_Latn | 14,860 |
J.B.S. Haldane's (1892-1964) biological speculations. | ABSTRACT J.B.S. Haldane's biological predictions and speculative writings are briefly evaluated with special reference to his book: Daedalus or Science and the Future (1923). | Treatment of widely available isocyanates with monohalolithium and dihalolithium carbenoids provides a valuable protocol for the one-pot preparation of α-halo- and α,α-dihaloacetamide derivatives. While monohalolithium carbenoids can be prepared by a smooth lithium–halogen exchange, the preparation of the corresponding dihalo compounds proved to be highly dependent on the base used to realize the deprotonation, with lithium 2,2,6,6-tetramethylpiperidine emerging as optimal. The clear advantages of the procedure are: (a) broad scope of isocyanates that can be employed; (b) preservation of the optical purity when chiral materials are used; (c) divergent access to different haloamides by simply selecting the homologating agents. We also report an application of Charette’s imidoyl triflate activation of a secondary amide to the synthesis of an α-chloro ketone and 15N NMR data for selected compounds. | eng_Latn | 14,861 |
Imino [4+4] cycloaddition products as exclusive and biologically relevant acrolein-amine conjugates are intermediates of 3-formyl-3,4-dehydropiperidine (FDP), an acrolein biomarker. | We demonstrated synthetically that the eight-membered heterocycles 2,6,9-triazabicyclo[3.3.1]nonanes and 1,5-diazacyclooctanes are the initial and exclusive products of the reaction, through an imino [4+4] cycloaddition, of biologically relevant amines with acrolein. The stabilities of the aminoacetals within the eight-membered heterocycles determined whether the product was subsequently transformed gradually into the 3-formyl-3,4-dehydropiperidine (FDP), which is widely used as an oxidative stress marker. The reactivity profiles discovered in this study suggested that some of the imino [4+4] cycloaddition products are reactive intermediates of FDP and contribute to the mechanisms underlying the oxidative stress response to acrolein. | A simple and cost-saving process was developed for the preparation of 1-boc-3,3-dimethyl-piperazine starting from 2-amino-2-methyl-propionic acid and glycine. | eng_Latn | 14,862 |
Substituent effects on thermal rearrangement of 3- (substituted phenyl)-4-(p-tolyl)-1,2,4-oxadiazole-5(4H)- thiones | The kinetics of the rearrangement of 3-(substituted phenyl)-4-(p-tolyl)-1,2,4-oxadiazole-5(4 H)-thiones in solution were determined in the temperature range 160-200°C. From the correlation of logk against s, it was found that for m-Me, p-Cl and p-CN, the compounds rearrange with the homolytic cleavage of the N—O bond, whereas for p-Me, H and m-NO2, the rearrangement occurs with the heterolytic cleavage of the N—O bond. In comparison with the uncatalysed rearrangement, Cu catalysis greatly increased the rate of the rearrangement of 3-( m-chlorophenyl)-4- (p-tolyl)-1,2,4-oxadiazole-5(4 H)-thione at 166 °C. Copyright © 2000 John Wiley & Sons, Ltd. | ABSTRACT Several new thienopyridine and methylthioether derivatives have been synthesized. New synthesis of pyrido[2,3-b]-thieno[3,2-d]pyrimidine and penta substituted benzene were achieved. | eng_Latn | 14,863 |
Raney metal catalysts: I. comparative properties of raney nickel proceeding from Ni-Ai intermetallic phases | Abstract Raney nickel catalysts, prepared from well defined pure phases, have been characterised by bulk composition, total and nickel surface areas, structure, activity and sensitivity to sulfur compounds. The catalyst formed from the Ni 2 Al 3 phase has 3 times more residual aluminium than that obtained from the NiAl 3 phase and it also develops the highest surface areas. Raney nickel prepared from a commercial 50–50 wt% Ni-AI alloy is a mixture of the samples obtained from the two pure phases. The origin of the catalyst has no effect upon either its activity and selectivity to benzene and isoprene hydrogenation or its catalytic properties in presence of thiophene or t-butyl mercaptan. | New ruthenium(III) complexes of the type [RuX2en2] A(en = ethylenediamine, X2= C2O4, Cl H2O, Cl l, Cl2, Br2, or l2; A = Cl, Br, l, ClO4, or p-Me·C6H4·SO2·O) have been isolated, together with complexes of the related ligands triethylenetramine and optically active propylenediamine. Magnetic susceptibilities show that all the compounds have the spin-paired d5 configuration. The cation [RuCl2en2]+ has been resolved into its optical enantiomorphs, and its structure related to that of other bis(ethylenediamine)ruthenium(III) compounds, all of which are assigned a cis configuration. Ultraviolet, visible, and infrared spectra are reported, and the use of infrared spectra in the detection of geometrical isomerism is discussed. New mono-ethylenediamine complexes [RuX4en]– have been isolated in combination with the cations [RuX2en2]+ and (phen H)+(phen = 1,10-phenanthroline; X = Cl, Br, l, or ½C2O4). | eng_Latn | 14,864 |
Mononuclear heterocyclic rearrangements. Part 4 Synthesis and characterization of the E-isomer phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole† | 3-Benzoyl-5-phenyl-1,2,4-oxadiazole (I) with phenylhydrazine in acetic acid gives the two geometrical isomers, phenylhydrazones II-Z and II-E, which have been characterized by uv-visible, ir, and nmr spectra. The possible II-E ⇌ II-Z isomerization as well as the rearrangement of II-Z and of II-E into 2,5-diphenyl-4-benzoylamino-1,2,3-triazole (III) has been pointed out. | Abstract 2-Substituted-5,5-diphenyl-2-oxazolin-4-ones 1 are prepared in good to high yields by reaction of diphenyl ketene and N-acylsulfilimes. | eng_Latn | 14,865 |
Copper-Catalyzed Aerobic 6-Endo-Trig Cyclization of β,γ-Unsaturated Hydrazones for the Divergent Synthesis of Dihydropyridazines and Pyridazines | A divergent synthetic strategy to 1,6-dihydropyridazines and pyridazines through Cu(II)-catalyzed controllable aerobic 6-endo-trig cyclization was developed. The selectivity can be rationally tuned via the judicious choice of reaction solvent. It was found that the 1,6-dihydropyridazines were obtained in moderate to high yields with CH3CN as the reaction solvent, whereas employment of AcOH directly afforded pyridazines in up to 92% yields, probably arising from the oxidation of the in situ generated 1,6-dihydropyridazines. | In the present investigation a series of some novel synthetic Chalcones (2a-d) and their heterocyclic analogs such as Isoxazolines (3a-d), Pyrimidines (4a-d), Pyrazolines (5a-d), Benzodiazepines (6a-d) and | eng_Latn | 14,866 |
Synthesis and X-ray Crystal Structures of Two Luminescent Imidazopyridinium Derivatives from the Corresponding N-(aryl)-Pyridine-2-aldimines | Syntheses and X-ray structural characterizations of two new luminescent imidazopyridinium derivatives, 2-(phenyl)-N(3)-(4(methyl)phenyl)-imidazo[1,5a] pyridinium perchlorate (1) and 2-(pyridyl)-N(3)-(4-(chloro)phenyl)-imidazo[1,5a] pyridinium perchlorate (2) are reported. The compounds are prepared in one step from N-(4-(methyl)phenyl) pyridine-2-aldimine and N-(4-(chloro)phenyl) pyridine-2-aldimine respectively in a transformation mediated by Mn(OAc)2-KMnO4 mixture. It is found that the molecular structures of the two compounds are similar. In the solid state, 1 forms a three-dimensional network through a series of hydrogen bonds between the cations and anions in the lattice while 2 forms a similar but less extensively linked network. The substitution of hydrogen at the 2-position of the imidazopyridinium ring by phenyl or 2-(pyridyl) affects the nature of their first excited states as detected by changes in their emission and absorption spectra. | Objective: To design a new synthetic technology of the anti-malarial drug lumefantrine.Methods: Industrial fluorine was used as starting material.In the presence of manganese dioxide and using glacial acetic acid as solvent,inletting hydrogen chloride gas and 2,7-dichlorofluorene were produced.Then,using anhydrous AlCl3 as catalyst,2,7-dichlorofluorene reacted with chloracetyl chloride to produce 2,7-dichloro-4-chloracetyl fluorene.Finally,the "one-pot reaction" was used for the reduction,amination and condensation reaction to obtain lumefantrine.Results and Conclusion: The total yield of this technology was over 40% based on fluorene,its processing steps were less than those of previous technologies,and the operation was simple.Thus,the new method is much more advanced and the new process route is much more suitable for industrial production. | eng_Latn | 14,867 |
Comparing Amide-Forming Reactions Using Green Chemistry Metrics in an Undergraduate Organic Laboratory | In this laboratory experiment, upper-division undergraduate chemistry and biochemistry majors investigate amide-bond-forming reactions from a green chemistry perspective. Using hydrocinnamic acid and benzylamine as reactants, students perform three types of amide-forming reactions: an acid chloride derivative route; a coupling reagent promoted method; and a boric acid catalyzed condensation. After isolation of the common product, students assess the reactions using the 12 Principles of Green Chemistry and several green chemistry metrics: atom economy; reaction mass efficiency; process mass intensity; and the EcoScale. In addition to assessing what route is the greenest, students also compare the metrics to discern what aspects of green chemistry each metric captures. In order to extend sustainability to economic considerations, the projected “front-end” cost of synthesizing a kilogram of the amide is calculated based on data from each reaction. The experimental work is conducted over two 3 h laboratory pe... | Abstract With this we like to communicate on the use of the reagent, 2-bro-mo-N-(2-bromoethyl)-N-carbethoxyethanamine 1, in the synthesis of 4,4 disubstituted piperidines. The latter are of interest in the field of neuroleptics1, local anesthetics2, analgetics3,4 and antidiarrhoeal agents5. Synthesis of some of them can be realized starting from an appropriate 4-functionalized piperidine1. A method using the alkylation of active methylene compounds with N-mustard derivatives of type 2a,b is most useful2-4,6. Also the N-sulfonyl protected derivative 2c has been used, with variable success; however if refunctionalization on the piperidine N-atom is required, the sulfonyl group is not easily removed. | eng_Latn | 14,868 |
Iodobenzene-Catalyzed Oxidative Cyclization for the Synthesis of Highly Functionalized Cyclopropanes | An iodobenzene-catalyzed oxidative cyclization of Michael adducts of activated methylene compounds with nitroolefins or chalcones is developed. mCPBA is used as oxidant together with Bu4NI for the generation of a highly reactive iodine(III) species to mediate the cyclopropanation via a ligand exchange and reductive elimination process. A range of highly functionalized cyclopropanes are synthesized with high diastereoselectivities. | Rotational isomeric state theory provides a relatively simple formalism for the evaluation of the persistence vector, a, for a chain that can be represented by a repeating sequence of independent virtual bonds. The numerical problem can be reduced to the computation of the averages of the elements in the transformation matrices, . This approach is applied for the evaluation of the limiting length of a for poly(benzobisorazole) and poly(benzobisthiazole) as the molecular weight becomes infinite. Some of the elements in can be assigned by symmetry arguments and the remaining nonzero elements are deduced from molecular dynamics theory. | eng_Latn | 14,869 |
First examples of a modulated bridging mu(2)-1:2kappan-triazine in double helical silver compounds. experimental and theoretical evidence. | The synthesis of several silver double helices containing bis(3,5dimethylpyrazolyl)-6-(R)-s-triazine ligands is described. The structure of two of them has been determined by X-ray difraction. Both derivatives represent the first reported examples of a new interaction mode for a triazine ring that involves a triazine N atom bridging two metal centers. Argentophilic contacts are also present. The Ag-N and Ag-Ag interactions have been demonstrated by theoretical studies, which also showed the clear influence of weak interactions with the counteranion and the effect of the symmetry of the triazine substituent. The different donor characters of these substituents allows a modulation of the strength of the bridging Ag-N(triazine) interaction. Double pi-pi stacking, anion-pi interactions, hydrogen bonds, and hydrophobic effects are observed in an unusual highly symmetrical interpenetrated three-dimensional superstructure. | Research progress of TRIP steel and ZrO2-TRIP steel matrix composites are introduced.The preparation,microstructure,mechanical properties and the existing problems of ZrO2-TRIP steel matrix composites are elaborated.The solutions to these problems are pointed out.Finally the development direction of ZrO2-TRIP steel matrix composites is predicted. | eng_Latn | 14,870 |
Novel bivalent positive allosteric modulators of AMPA receptor | A positive allosteric modulator of AMPA receptors has been designed using computer-aided molecular modeling techniques. It possessed a record high experimentally confirmed potency in the picomolar concentration range and belongs to a new type of bivalent AMPA receptor ligands containing bicyclo[3.3.1]nonane scaffold. The suggested structure could serve as a basis for further optimization and development of drugs for the treatment of neurodegenerative diseases, cognition enhancement, and improvement of memory. | Carbazole-based donor–acceptor compounds with tunable HOMO–LUMO gaps were synthesized by Suzuki and Sonogashira cross-coupling reactions. Their optical and electrochemical properties were fully characterized. The results | eng_Latn | 14,871 |
Biaryl-based macrocyclic and polymeric chiral (salophen)Ni(II) complexes: synthesis and spectroscopic study. | Polymeric/oligomeric and macrocyclic (salophen)Ni(II) complexes have been synthesized starting from both an achiral biphenol dialdehyde and an optically active BINOL dialdehyde. It was found that these polysalophens contain nonplanar coordination of Ni(II) units that are paramagnetic. This is different from the previously reported (salophen)Ni(II) complexes which are square planar and diamagnetic. The nonplanar (salophen)Ni(II) units make the new polymeric Ni(II) complexes different from the helical structure proposed for chiral biaryl-based polymers containing square-planar (salophen)Ni(II) units. The copolymerization of the chiral binaphthyl monomer with the achiral biphenyl monomer demonstrates that the chirality of the binaphthyl unit is not propagated along the biphenyl polymer chain. | Reaction between arolychlorides and 1-(2-aminobenzyl)-2-cyanopyrrole afforded the corresponding aroylamides, which were transformed by intramolecular cyclization into 11-aryl-3-cyano-5H-pyrrolo[2,1-c] [1,4] benzodiazepines. Hydrolysis of cyanoderivatives furnished the corresponding amides or acids depending on the reaction conditions. Decarboxylation and reduction of some derivatives to afford 11-aryl-5H-pyrrolo[2,1-c] [1,4] benzodiazepines and 11-aryl-3-cyano-10,11-dihydro-5H-pyrrolo[2,1-c] [1,4] benzodiazepines are described. | eng_Latn | 14,872 |
Structure ofEcballium elateriumtrypsin inhibitor II (EETI-II): a rigid molecular scaffold | The Ecballium elaterium trypsin inhibitor II (EETI-II) belongs to the family of squash inhibitors and is one of the strongest inhibitors known for trypsin. The eight independent molecules of EETI-II in the crystal structure reported here provide a good opportunity to test the hypothesis that this small cystine-knot protein (knottin) is sufficiently rigid to be used as a molecular scaffold for protein-engineering purposes. To extend this test, the structures of two complexes of EETI-II with trypsin have also been determined, one carrying a four-amino-acid mutation of EETI-II. The remarkable similarity of these structures confirms the rigidity of the molecular framework and hence its suitability as a molecular scaffold. | [Formula 1] The present invention provides a group of piperazine derivatives mesylate, and a method for the preparation of these mesylates in high yield and high purity economical way. According to the method of the present invention, synthesis of the piperazine ring and the mesylate product are combined in a single reaction step. The present invention, X is a bicyclic heterocyclic phenyl group and Y is methyl, (optionally substituted by fluorine in some cases) ethyl, cycloalkyl (3-7C) methyl, benzyl or m- phenyl benzyl in which, on the mesylate of the compound of formula (1). | eng_Latn | 14,873 |
Antitussive effect of SR 48968, a non-peptide tachykinin NK2 receptor antagonist. | The antitussive effects of SR 48968, a non-peptide tachykinin NK2 receptor antagonist, were investigated on citric acid-induced cough in the unanesthetized guinea-pig and compared with the effects of codeine. SR 48968 (0.01-0.3 mg/kg i.p.) inhibited in a dose-dependent manner the number of coughs induced by inhalation of an aqueous solution of citric acid with an ED50 of 0.1 mg/kg (0.17 mumol/kg). Under similar conditions, the codeine ED50 was 8 mg/kg (27 mumol/kg). Naloxone, an opioid receptor antagonist, abolished the effects of codeine but did not modify the effects of SR 48968. These data suggest that NK2 receptor stimulation might play an important role in the regulation of the cough reflex and that SR 48968 could be a potential antitussive agent. | Abstract : The solid and liquid state steric configurations of several bis-(N-alkylsalicylaldimino)-nickel (II) complexes were examined spectrophotometrically and by magnetic and dielectric polarization measurements. It was found that the n-propyl derivatives are planar, the t-butyl derivatives pseudo-tetrahedral, and the secalkyl derivatives either planar or pseudo-tetrahedral. Thermochemical, electronic, and steric implications are discussed. R-N-salicylaldimine-cobalt(III) complexes were found to exist in the trans-octahedral configuration only. | eng_Latn | 14,874 |
Kinetics and mechanism of hydrolysis of acetamides in metal-ion redox systems | The hydrolysis ofN-methylacetamide andN,N-dimenthylacetamide in the presence of cobalt(III) and cerium(IV) has been studied in perchloric acid in the range 10–50° C. The reduction of metal ions and the hydrolysis of amides are very slow processes. However, it appears that reduction of metal ion is coupled with the hydrolysis of amides in such a way as to give enhanced rates for the two processes. The reaction requires one mole of the metal ion for one mole of amide. The rate is proportional to the acid concentration and is independent of ionic strength. Activation parameters have been calculated and reaction mechanisms proposed. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,875 |
catena-Poly[[[bis(1,3-diaminopropane-N,N')nickel(II)]-μ-(4,4'-bipyridine-N:N')] diperchlorate] | In the structure of the title polymer, {[Ni(C 3 H 10 N 2 ) 2 (C 10 H 8 N 2 )](ClO 4 ) 2 } n , the metal atom is in a slightly distorted octahedral NiN 6 geometry surrounded by four N atoms of two 1,3-diaminopropane ligands in equatorial positions [2.131(2) and 2.145 (2) A] and two N atoms from 4,4'-bipyridine ligands in axial sites [2.165 (3) and 2.205(3) A]. The 4,4'-bipyridine ligands bridge neighbouring Ni II atoms to form polymeric chains in the lattice. | The selectivity of the CO2 photoreduction reaction in the presence of water vapour can be modulated by the band structure of a g-C3N4 photocatalyst. The major products obtained using bulk g-C3N4 with a bandgap of 2.77 eV and g-C3N4 nanosheets with a bandgap of 2.97 eV are acetaldehyde (CH3CHO) and methane (CH4), respectively. | vie_Latn | 14,876 |
Synthesis and 12-Helical Secondary Structure of β-Peptides Containing (2R,3R)-Aminoproline | (2R,3R)-Aminoproline, a pyrrolidine-based β-amino acid, was synthesized and incorporated into hexa-β-peptide 4. This residue confers water solubility when the ring nitrogen is protonated and allows for 12-helix formation in aqueous solution. Circular dichroism spectra display the 12-helical signature, and 12-helical structure was confirmed by 2D NMR analysis. | OBJECT OF THIS PATENT are compounds of formula (I) or salts thereof, where R1, R (squared) are H, an aliphatic saturated or (SUBST.), Phenyl (n.), Or R1 YR (AL SQUARE) together with the nitrogen atom to which they are attached form a heterocyclic OF FORMULA 1 rING, being independently an integer of 1 to 3, R3 is H, an aliphatic saturated or (SUBST.) A REST phenyl, benzyl or phenethyl (n.), OR (squared) and R3 are together form a chain alkylene, R4 is hydrogen, an aliphatic saturated or alkoxy, and R5 is a pyrimidinyl (n.), triazinyl, triazolyl or A REST bicyclic nitrogenous heterocyclene. These compounds have valuable qualities HERBICIDES OR PLANT GROWTH REGULATORS. | eng_Latn | 14,877 |
Synthesis and antiviral evaluation of unnatural beta-L-enantiomers of 3'-fluoro- and 3'-azido-2',3'-dideoxyguanosine derivatives. | Abstract 3′-fluoro-2′3′-dideoxy- (3) and 3′-azido-2′,3′-dideoxy- (4) β-L-ribofuranonucleoside derivatives of guanine have been synthesized and their antiviral properties examined. All these derivatives were regioselectively and stereospecifically prepared by glycosylation of 2-N-acetyl-6-O-(diphenylcarbamoyl)guanine 5 with a suitable peracylated L-xylo-furanose sugar 6, followed by appropriate chemical modifications. The prepared compounds were tested for their activity against HIV and HBV viruses, but they did not show significant activity. | Liquid N-methyldisilazane, (SiH3)2NMe, disproportionates when mixed with ammonia or methylamine at or below room temperature to give silane, hydrogen, and chiefly involatile products. Moderate heating is necessary with pyridine, trimethylamine, or tetradrofuran. Rates of silane evolution lie in the order: NH3 > NH2Me C5H5N NMe3 > C4H8O. N-Phenyldisilazane reacts similarly, but more slowly, and the order of bases is: NH3 > NH2Me PhNH2∼ C5H5N. From the stoicheiometry of the reactions and the properties, including i.r. spectra, of the products, it appears that tertiary amines yield essentially linear oligomers with SiH3NR end-groups. Primary amines and ammonia induce amine exchange and form cross-linked polmers with NR bridging groups and chiefly NHR end-groups. A mechanism to account for these facts is proposed. Polymer derived from (SiH3)2NMe and methylamine slowly reduces gaseous methylamine to ammonia at room temperature. | eng_Latn | 14,878 |
Fine structures of 14N NQR lines in hydrazine derivatives | Abstract The nitrogen-14 NQR lines of symmetric hydrazine derivatives, diacetylhydrazine and diformylhydrazine, have been investigated at 77 K by the use of a pulsed NQR spectrometer and the slow beats of the echo envelopes were observed on every six NQR lines. Taking into account for the intramolecular magnetic dipole coupling between nitrogen nuclei, the energy level scheme for the nitrogen nucleus was calculated using a perturbation theory and the experimental results were explained clearly. It was elucidated that each line was composed of four spectra having a center of symmetry. | Abstract In this paper, we investigate stable perturbations and their characterizations for various types of outer inverses, such as generalized, { 2 , 3 } -, { 2 , 4 } -, { 2 , 5 } -, { 1 , 2 , 3 } -, { 1 , 2 , 4 } -, Moore–Penrose, group, Drazin and generalized Drazin inverses. Some known results are improved and extended. | eng_Latn | 14,879 |
N,N,N′,N′‐Tetramethylethane‐1,2‐diamine–N‐hydroxybenzensulfonamide (1/2): an adduct of Piloty's acid | The title compound, C6H16N2·2C6H7NO3S, consists of a strongly hydrogen-bonded adduct of N,N,N′,N′-tetramethylethane-1,2-diamine (tmen) and undissociated N-hydroxybenzensulfonamide (Piloty's acid, PA). The diamine molecule sits on a center of symmetry at the mid-point of the central C—C bond. The C—S—N—O linkage in PA adopts a syn geometry. | Abstract A convenient microwave-assisted methodology is developed for the generation of 5-chloro-3-(dimethylamino)pyrazin-2(1H)-ones. The method entails a chemoselective desulfitative removal of a phenylthioether bond upon DMF/H2O treatment in the presence of sodium carbonate, yielding the desired compounds in 73–96%. | eng_Latn | 14,880 |
N-metalated imines by reaction of 1,1-diethoxybut-2-ene with aromatic nitriles, as useful intermediates for the synthesis of substituted pyrimidines and cyclopentenones. | A new approach to the synthesis of pyrimidines and cyclopentenones is described. The method exploits the reactivity of alpha,beta-unsaturated acetals with aromatic nitriles in the presence of the Schlosser's superbase LIC-KOR. | A ring-expanded bryostatin analogue was synthesized by utilizing a Ru-catalyzed tandem tetrahydropyran formation, a Pd-catalyzed tandem dihydropyran formation, and a ring-closing metathesis (RCM) as key steps. The analogue possesses potent antitumor activity against the NCI-ADR cancer cell line with an IC50 of 123 nM. | eng_Latn | 14,881 |
9-[4-(Azidomethyl)phenyl]-9H-carbazole-3-carbonitrile | In the title compound C20H13N5, the dihedral angle between the carbazole ring system (r.m.s. deviation = 0.027 A) and the pendant benzene ring is 55.08 (6)°. One of the azide N atoms is disordered over two positions in a 0.65 (2):0.35 (2) ratio. In the crystal, aromatic π–π stacking is observed [minimum centroid–centroid separation = 3.6499 (13) A] as well as inversion-dimers connected by pairs of weak C—H⋯π interactions. | The easy cycloaddition of ureas with alkynyl alkoxy biscarbene complexes afforded, in fairly good yields, new biscarbene uracil analogs. X-ray structural data is reported for the dimethyluracil biscarbene complex. By changing the reaction conditions, a new non symmetric complex was obtained whose reaction with ethylenediamine afforded a new tetrakis amino carbene complex. | eng_Latn | 14,882 |
Correction for An organometallic route to long helicenes | CHEMISTRY Correction for "An organometallic route to long helicenes," by Petr Sehnal, Irena G. Stara, David Saman, Milos Tichy, Jifi Misek, Josef Cvacka, Lubomir Rulisek, Jana Chocholousova, Jaroslav Vacek, Grzegorz Goryl, Marek Szymonski, Ivana Cisafova, and Ivo Stary , which appeared in issue 32, August 11, 2009, oiProc Nati Acad Sci USA (106:13169-13174; first published July 24, 2009; 10.1073/pnas.0902612106). The authors note that due to a printer's error, the legend for Scheme 2 appeared incorrectly in part. The absolute configuration prefixes appeared as lower-case letters but should have been capitalized. Additionally, part of the legend for Scheme 3 did not appear. The schemes and their corrected legends appear below. | Abstract The reaction of 2-Coumarylidenemalononitriles 1a,b with some active methylene, bidentates and ketoketene S, S or N, S acetals affords a series of new spiro heterocyclic systems. | eng_Latn | 14,883 |
Method for synthesizing 4-dimethylamino pyridine and analogues thereof | The invention provides a method for synthesizing 4-dimethylamino pyridine and analogues thereof, wherein a reaction formula is shown in the specification, and in the formula: R1 and R2 respectively represents hydrogen, alkyl, alkyl sulfhydrate, phenyl, benzyl, cycloalkyl of -(CH2)n-, or -(CH2)2O(CH2)-, wherein n=2-6. Reaction alkali may be cesium carbonate, potassium phosphate, pyridine, triethylamine, sodium bicarbonate, potash, sodium hydroxide (potassium) and sodium alkoxide (potassium). A reaction solvent may be 1,4- dioxane, toluene, dimethyl sulfoxide, dimethyl formamide, acetonitrile, tetrahydrofuran and acetone. The reaction is carried out by conventional heating. The method has advantages of easily available raw material, simple technology and mild reaction condition. | Experiments on small laboratory animals were made to study local anesthetic, antinociceptive and antihypoxic properties of 6 new derivatives of 1-methylpiperidine. A substance coded phi AB-8 (1-methyl-4-vinylethynil-4-benzoyl hydroxypiperidine hydrochloride) was found to exert a pronounced local anesthetic and an antihypoxic actions. | eng_Latn | 14,884 |
Studies of continuous-flow synthesis of nonpeptidal bistetrahydrofuran moiety of Darunavir | The use of continuous-flow chemistry has shown to be an important tool in improving API manufacture. In the present paper, we report the use of continuous-flow reactors in the synthesis of the bicyclic side chain of antiretroviral Darunavir. | Abstract Substituted indoles, carbazoles, benzothiophenes and benzofurans are important motifs in the pharmaceutical industry. Herein we report a novel, regioselective method to introduce alkyl substituents into position ortho of nitro groups by the addition of a Grignard reagent followed by subsequent oxidation with DDQ. | eng_Latn | 14,885 |
SYNTHESIS AND STRUCTURAL STUDIES OF A NEW CLASS OF ORGANOBIMETALLIC COMPOUNDS | Abstract A new class of organobimetallic compounds of general formula (SCN)2Zn(NCSHgR)2 and (SCN)2Co(NCSHgR)2 (R=CH3, C2H5, n-C4H9 and iso-C4H9) have been synthesized. The cobalt analogs have been found to act as Lewis acids hence their complexes with pyridine, nicotinamide and 2,2 ' -bipyridyl have also been prepared. The corresponding zinc compounds decompose on reaction with these bases. These compounds have been characterized by elemental analyses, molar conductance, molecular weight determination, infrared spectral (4000–50 cm−1), electronic spectral and magnetic moment studies. These studies indicate that the Lewis acids are monomers and the cobalt or zinc and mercury atoms are connected through bridging thiocyanate groups. The cobalt or zinc atoms acquire a tetrahedral coordination geometry, whereas mercury retains its linearity. | On the basis of the organic chemistry bachelor thesis,according to the personal training and the study feature of Changzhou University,some useful innovation idea and methods were analyzed and concluded with the combination of organic chemistry reform experience.These methods and idea were help to mobilize the enthusiasm and initiative of participating in the experiment and to promote the students' practical ability. | yue_Hant | 14,886 |
Preparation and stereochemistry of some 1,1-disubstituted buta-1,3-dienes | The preparation of five (E)- and five (Z)-1,1-disubstituted buts-1,3-dienes is described and their stereochemistry assigned. The effect of the Z–E isomerism on the chemical shifts in the 13C and 1H n.m.r. spectra is discussed. | New ruthenium(III) complexes of the type [RuX2en2] A(en = ethylenediamine, X2= C2O4, Cl H2O, Cl l, Cl2, Br2, or l2; A = Cl, Br, l, ClO4, or p-Me·C6H4·SO2·O) have been isolated, together with complexes of the related ligands triethylenetramine and optically active propylenediamine. Magnetic susceptibilities show that all the compounds have the spin-paired d5 configuration. The cation [RuCl2en2]+ has been resolved into its optical enantiomorphs, and its structure related to that of other bis(ethylenediamine)ruthenium(III) compounds, all of which are assigned a cis configuration. Ultraviolet, visible, and infrared spectra are reported, and the use of infrared spectra in the detection of geometrical isomerism is discussed. New mono-ethylenediamine complexes [RuX4en]– have been isolated in combination with the cations [RuX2en2]+ and (phen H)+(phen = 1,10-phenanthroline; X = Cl, Br, l, or ½C2O4). | eng_Latn | 14,887 |
Ring opening reactions in glycidyl ethers by squaric acid and additives | Abstract The ring opening reactions of phenyl-, alkyl- glycidyl ethers and glycidyl methacrylate in the presence of the super acid and additives, N -methylol acrylamide, dicyandiamide, flajil, bromflajil and imidazol, were investigated. The rates of the ring opening reactions of the compositions, squaric acid:ethanol:glycidyl ethers (3 zero series V 0 ) and squaric acid:ethanol:glycidyl ethers:additives ( V 1 and V 2 ), were determined and the activity of the additives were compared. The activity of these additives correlated with H-bond formation is evaluated by IR spectroscopy. The A ′= A C–O–C / A int.standard ratios were calculated from A C–O–C and internal standard A CH 2 absorbancies, and the most available absorbancies for quantitative IR analyses were determined. H-bond formation was characterised with the shift of the absorption bands, the peak width at half height and the absorbancies for OH group were around 3500 cm −1 . | Abstract With this we like to communicate on the use of the reagent, 2-bro-mo-N-(2-bromoethyl)-N-carbethoxyethanamine 1, in the synthesis of 4,4 disubstituted piperidines. The latter are of interest in the field of neuroleptics1, local anesthetics2, analgetics3,4 and antidiarrhoeal agents5. Synthesis of some of them can be realized starting from an appropriate 4-functionalized piperidine1. A method using the alkylation of active methylene compounds with N-mustard derivatives of type 2a,b is most useful2-4,6. Also the N-sulfonyl protected derivative 2c has been used, with variable success; however if refunctionalization on the piperidine N-atom is required, the sulfonyl group is not easily removed. | eng_Latn | 14,888 |
Different structures for two very similar 2-benzoylpyridine azacyclothiosemicarbazones | 2-Benzoylpyridine piperidinyl- and hexamethyleneiminylthiosemicarbazones, HBzpip and HBzhexim, respectively, crystallize in a hydrogen bonded Z isomeric conformation with respect to the C7-N2 bond. The intramolecular hydrogen bond is between N3-H...N1, but the S atom is E to the azomethine nitrogen, N2, for HBzpip and Z for HBzhexim. HBzpip is the second ZE isomer known, but the first that does not have a formal hydrogen bond to N2. | OBJECT OF THIS PATENT are compounds of formula (I) or salts thereof, where R1, R (squared) are H, an aliphatic saturated or (SUBST.), Phenyl (n.), Or R1 YR (AL SQUARE) together with the nitrogen atom to which they are attached form a heterocyclic OF FORMULA 1 rING, being independently an integer of 1 to 3, R3 is H, an aliphatic saturated or (SUBST.) A REST phenyl, benzyl or phenethyl (n.), OR (squared) and R3 are together form a chain alkylene, R4 is hydrogen, an aliphatic saturated or alkoxy, and R5 is a pyrimidinyl (n.), triazinyl, triazolyl or A REST bicyclic nitrogenous heterocyclene. These compounds have valuable qualities HERBICIDES OR PLANT GROWTH REGULATORS. | eng_Latn | 14,889 |
Crystal and molecular structure of pyrrolidine dithio carbamate cobalt (III) chelate | Pyrrolidine dithio carbamate (pdtc) cobalt(III) chelate has been used as a coprecipitation matrix for obtaining preconcentration factors of 100 or more for analytical estimation of trace metals in natural waters. This chelate, suitable for bivalent and trivalent ions, crystallizes as dark green crystals in monoclinic space group C2/c with unit cell parametersa = 28.89 a,b = 14.39 a,c = 16.17 a andΒ = 104.2‡. X-ray crystallographic analysis of these crystals reveals that threepdtc are coordinated to a Co 0 3 + atom through their sulphur atoms, the six sulphur atoms forming a distorted octahedra around the metal atom at an average distance of 2.26 a. The thiocarbamate part of the ligands is nearly planar but the pyrrolidine rings are puckered. | TiCl((OPr)-Pr-i)(3) and NaBH(OAc)(3): an efficient reagent combination for the reductive amination of aldehydes by electron-deficient amines Sodium triacetoxyborohydride, NaBH(OAC)(3) with tri- isopropoxytitanium chloride, TiCl((OPr)-Pr-i)(3) is a useful reagent combination for reductive amination. Electron-deficient amines and heteroaromatic amines such as 2-aminopyrimidine and 2-aminothiazole can be reductively alkylated at room temperature to afford the corresponding secondary amines in good yields. © 2005 Elsevier Ltd. All rights reserved. | eng_Latn | 14,890 |
Axially Chiral Dicarboxylic Acid‐Catalyzed Asymmetric Imino Aza‐Enamine Reaction/Oxidation as a Strecker Reaction Surrogate. | The described method provides a practical tool for the preparation of the Strecker-type products without resorting to the use of highly toxic cyanide sources. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,891 |
Kinetic studies on the aminolysis of O-(2,4-dinitrophenyl)-cyclopentanone oxime in benzene | The reaction of O-(2,4-dinitrophenyl) cyclopentanone oxime with four primary alkylamines and a secondary arylamine, pyrrolidine, in benzene has been investigated. In pyrrolidinolysis, a third order dependence on [amine] has been observed, which has been explained on the basis of a cyclic transition state. The aminolysis with primary alkyl amines shows a normal dependence of second order on [amine]. | Objective To design and synthesis novel triazole antifungal derivatives and study the antifungal activity.Methods All the target compounds were prepared from 1,3- difluorobenzene via click reaction;The antibacterial activities of the title compounds were determined with broth dilution method.Results Twelve compounds were synthesized and characterized by 1H NMR and MS.All the title compounds exhibited potent antifungal activities against nearly all fungi tested.Conclusion The electronic effects of the substituents affected the activity of compounds,specifically the electron- donating groups. | eng_Latn | 14,892 |
The structure of 10-epi-lyfoline, a novel alkaloid from Heimia montana | The structure of 10-epi-lyioline [6], a biphenylquinolizidine alkaloid isolated from Heimia montana, has been established by nmr studies. The presumed structure of lyfoline [4] has been confirmed. | SummarySubstitution of acetyl for hydrogen in the NH2 group of the N-terminal serine, NH2 for OH” in the carboxyl of glutamine in position 5, and formyl for an amino hydrogen of lysine in positions 11, 15, 16, and 21 decreases or eliminates the ACTH-like activity of a synthetic tricosapeptide which duplicates the first 23 amino acids of naturally occurring ACTH. | eng_Latn | 14,893 |
C2-symmetrical bis ruthenium Diphosphine Ligand only with surface chirality | The invention relates the synthesis of C2-bis ruthenium doublephosphine ligand. The ligand can be used in metallic catalysis asymmetric reaction, and the ligand has the good reaction active and stereoselectivity. The R is -Me, -Et. | Abstract It is shown that oligonucleotide analogues containing alternating phosphodiester groups and cationic groups linked to phosphorus through an amidate bond hybridize to complementary RNA segments. An improved synthetic procedure for the alternating compounds is also described. | eng_Latn | 14,894 |
Influence of the solvent on the kinetics of the reversible recombination of 2-arylindan-1,3-dionyl radicals | 1. ::: ::: On the basis of obtained kinetic and thermodynamic parameters of the reaction of the reversible recombination of the 2-(4′-dimethylaminophenyl)indan-1,3-dionyl radical, it is established that the most dominating influence on the rate of this reaction is nonspecific solvation. ::: ::: ::: ::: ::: 2. ::: ::: Values of rate constants of the recombination of the 2-(4′-diphenylaminophenyl)indan-1,3-dionyl radical has a V-shaped dependence on the parameter ET, Strong solvation of this radical in chloroform converts the recombination reaction from a diffusion-controlled range to a kinetic range. | During the last eight years a number of aspects of ::: amide chemistry have been studied in the Chemistry ::: Department, University of Tasmania, under the direction ::: of Dr. J. B. Polya. Acylation of amides to diacylamines ::: was investigated, and satisfactory syntheses were developed ::: for unsymmetrical diacylamines (R1 ::: .CO.NH.CO.R2; R1≠R2 ). In some cases such diacylamines, through reacylation, ::: may form mixtures of the two corresponding ::: symmetrical diacylamines. Diacylamines react with hydrazines ::: to form 1:2:4-triazoles, which are convenient ::: derivatives indicating the structure of the diacylamine. ::: With a hydrazine R.NH.NH2 an unsymmetrical diacylamine ::: of the type indicated could form 1R-3R1 -5R2 - and ::: 1R-3R2 -5R1 -1:2:4-triazole. Proving the orientations of ::: the products from a number of diacylamines seemed a ::: promising way to investigate the mechanism of this triazole ::: synthesis. | eng_Latn | 14,895 |
The structure of halogenometallate complexes dissolved in both basic and acidic room-temperature halogenoaluminate(III) ionic liquids, as determined by EXAFS | The salts [MeEtim]2[MCl4]([MeEtim]+= 1-methyl-3-ethylimidazolium; M = Mn, Co, or Ni) are shown by EXAFS to dissolve in basic [MeEtim]Cl–AlCl3 ionic liquids to yield four-co-ordinate [MCl4]2–, and to dissolve in acidic [MeEtim]Cl–AlCl3 ionic liquids to yield six-co-ordinate [M(AlCl4)3]– anions. | PURPOSE: A novel method for preparing entecavir and a novel intermediate used for the same are provided to easily produce a large amount of novel intermediates. CONSTITUTION: A method for preparing entecavir of chemical formula 1: a step of hydrolyzing alpha-exomethylene compound of chemical formula 2 to synthesize a compound of chemical formula 3; a step of reacting the compound of chemical formula 3 with a purine compound of chemical formula 4 by Mitsunobu reaction to obtain a nucleoside compound of chemical formula 5; a step of reacting the compound of chemical formula 5 with tetrabutyl ammonium fluoride to obtain a compound of chemical formula 6; and a step of hydrolyzing the compound of chemical formula 6. | eng_Latn | 14,896 |
Synthesis of Substituted 2,3-Benzodiazepines | A new, four-step synthetic route for substituted 2,3-benzodiazepines 1, starting from aldehyde 4, was developed with excellent overall yields. This route included the 1,2-addition of various aromatic Grignard reagents to 4, PCC oxidation, and aerobic Wacker-type oxidation of the olefinic group of 6, followed by condensation of the resulting 1,5-dicarbonyl 7 with N2H4. Isoquinolones 9 were obtained when an aldehyde group was used instead of a ketone. The key structures were confirmed by X-ray single-crystal diffraction analysis. | The invention discloses a method for preparing Zyprexa crystal form II. The method for preparing the Zyprexa crystal form II comprises the following steps of: dissolving a Zyprexa crude product into acetonitrile; cooling and crystallizing; washing the obtained crystal with ethyl acetate or methylbenzene; and drying to obtain the Zyprexa crystal form II. Compared with the prior art, the method has the advantages of effectively controlling residual quantity of the solvent acetonitrile and contributing to market competition, along with high purity in products. | eng_Latn | 14,897 |
Efficient synthesis, structure, and antimicrobial activity of some novel N- and S-beta-D-glucosides of 5-pyridin-3-yl-1,2,4-triazoles. | Glucosidation of some 4-amino- and 4-arylideneamino-5-(pyridin-3-yl)-2,4-dihydro-[1,2,4]-triazole-3-thiones with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide followed by chromatographic separation gave the corresponding N- and S-beta-D-glucosides. The structure of these two regiosiomers was established chemically and spectroscopically. Deamination as well as deacetylation of some selected nucleosides have been achieved. Antimicrobial screening of 14 selected compounds resulted in their activity against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. | OBJECT OF THIS PATENT are compounds of formula (I) or salts thereof, where R1, R (squared) are H, an aliphatic saturated or (SUBST.), Phenyl (n.), Or R1 YR (AL SQUARE) together with the nitrogen atom to which they are attached form a heterocyclic OF FORMULA 1 rING, being independently an integer of 1 to 3, R3 is H, an aliphatic saturated or (SUBST.) A REST phenyl, benzyl or phenethyl (n.), OR (squared) and R3 are together form a chain alkylene, R4 is hydrogen, an aliphatic saturated or alkoxy, and R5 is a pyrimidinyl (n.), triazinyl, triazolyl or A REST bicyclic nitrogenous heterocyclene. These compounds have valuable qualities HERBICIDES OR PLANT GROWTH REGULATORS. | eng_Latn | 14,898 |
Design of aminobenzothiazole inhibitors of Rho Kinases 1 and 2 utilizing PKA as a structure surrogate | We describe the design, synthesis, and structure-activity relationships (SARs) of a series of 2-aminobenzothiazole inhibitors of Rho kinases (ROCKs) 1 and 2, which were optimized to low nanomolar potencies by use of protein kinase A (PKA) as a structure surrogate to guide compound design. A subset of these molecules also showed robust activity in a cell-based myosin phosphatase assay and in a mechanical hyperalgesia in vivo pain model. | Rotational isomeric state theory provides a relatively simple formalism for the evaluation of the persistence vector, a, for a chain that can be represented by a repeating sequence of independent virtual bonds. The numerical problem can be reduced to the computation of the averages of the elements in the transformation matrices, . This approach is applied for the evaluation of the limiting length of a for poly(benzobisorazole) and poly(benzobisthiazole) as the molecular weight becomes infinite. Some of the elements in can be assigned by symmetry arguments and the remaining nonzero elements are deduced from molecular dynamics theory. | eng_Latn | 14,899 |
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