Synthesis and spectral properties of 2-methyl-5-aryl-1,3,4-oxadiazoles

By heterocyclization of 1-acyl-2-aroylhydrazines under the influence of strong dehydrating substances, a series of 2-methyl-5-aryl-1,3,4-oxadiazoles has been synthesized and their UV, IR, and PMR spectra have been investigated. Through analysis of data on the influence of substituents on the position of the maximum in the electronic absorption spectrum, together with calculated data, it has been shown that the long-wave band of 2-methyl-5-phenyl-1,3,4-oxadiazole is due to an S₀–S₁ transition of the –^* type and that it is a charge transfer band for transfer from the phenyl radical to the oxadiazole ring; the 1,3,4-oxadiazole ring as a substituent has an electron-acceptor character.Institute of Single Crystals, National Academy of Sciences of the Ukraine, Khar'kov 310001. Khar'kov State University, Khar'kov 310077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 816–821, June, 1997.     

Flavonoids of Bidens tripartita. III

Summary It has been established that substance 4, isolated previously fromBidens tripartita, is (R-2)isookanin 7-O--D-glucopyranoside [(R-2)flavanomarein]. The compound isolated is a new one for the genusBidens L.Khar'kov State Pharmaceutical Institute. Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 144–147, March–April, 1975.     

Phenolic compounds of Ononis arvensis the structure of onogenin

Summary From the roots ofOnonis arvensis L. a new isoflavone has been isolated with mp 213–214° C which has been called onogenin. On the basis of the results of a study of its UV, IR, NMR, and mass spectra, the structure of 7-hydroxy-6-methoxy-3,4-methylenedioxyisoflavanone is proposed for onogenin.Khar'kov State Pharmaceutical Institute. Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 354–357, May–June, 1975.     

Synthesis of aromatic derivatives of 1,5-benzodiazepine in the reaction of 4-nitro-o-phenylenediamine with chalcone dibromides

The reaction of 4-nitro-o-phenylenediamine with 4-nitro-4-R-chalcone dibromides affords the corresponding -(2-amino-4-nitroanilino)chalcones; x-ray diffraction data indicate that these are the Z-isomers. Experiments have been perfortned to determine the conditions required for cyclization of these compounds into 2, 4-diaryl7(8)-nitro-1, 5-benzodiazepines. In the solid phase or in ethanol solutions, these latter compounds exist primarily in the 3H tautomeric form; but in DMSO solutions, the 1H form predominates.Khar'kov State University, Khar'kov 310077. Institute of Heteroorganic Chemistry, Russian Academy of Sciences, Moscow 117813. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 950–958, July, 1995. Original article submitted June 30, 1994; revision submitted April 3, 1995.Deceased     

Intramolecular interactions in series of oxazole, oxadiazole, and triazole derivatives

A comparison of the PMR spectra of 5-phenyl-2-methyl derivatives of oxazole, 1,3,4-oxadiazole, and 1, 3, 4-triazole with the spectrum of toluene leads to the conclusion that the electron-acceptor character of the heterocycles drops off in the order oxadiazole >oxazole>triazole. The conduction of electronic effects of the substituents by the oxazole ring is at the level of benzene; the 1, 3, 4-oxadiazole ring accomplishes the transmission somewhat better, and the 1,3,4-triazole ring more weakly, than in the case of benzene. The formation of H-complexes with a 11 composition in a system consisting of the azole, phenol, and carbon tetrachloride was investigated by means of IR spectroscopy. The relative n-donor strength, of the heterocycles decreases in the series triazole >oxazole> oxadiazole. The effectiveness of transmission of electronic influence of the substituents in the phenyl radical on the pyridine nitrogen atom, which is the center of complexation, decreases in the series oxazole >oxadiazole>triazole.Khar'kov State University, Khar'kov 310077. Institute of Single Crystals, Academy of Sciences of the Ukraine, Khar'kov 310001. Translated from Khimiya Geterotsiklicheskikh, Soedinenii, No. 6, pp. 811–815, June, 1997.     

Electronic structure and absorption spectra of products from single-electron reduction of derivatives of 4,4′-dipyridyl

The Hartree-Fock absolute method has been used in the -electron approximation to investigate the absorption spectra of a number of cation-radical salts of derivatives from 4,4-dipyridyl with the objective of explaining the interrelation between their electronic structure and the nature of the set of these salts with the spectroscopic characteristics. The characteristic absorption spectrum of cation-radicals of 4,4-dipyridyl and its derivatives is formed due to the merging of three absorption bands of different natures, localized on the dipyridyl fragment. In the absorption spectra of products from single-electron reduction of dications of 4,4-dipyridyl a band is observed from charge transfer between the cation-radical and the dication, and also an absorption band of the -dimers being formed as a result of spin-spin interaction of the cation-radicals.Scientific Publications of the "Monocrystal Reagent" Association, Khar'kov, Khar'kov University. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 6, pp. 752–757, November–December, 1987.The authors express their deep gratitude to I. V. Krivoshei for constant interest in the work, attention and support, to A. V. Luzanov and V. É. Umanskii for valuable discussions and making available calculation programs for electronic characteristics of the molecules.     

Molecular structure and conformations of a sterically hindered aryl derivative of 1,3,4-oxadiazole containing an o,o′-biphenyl ring system

The structure of sterically hindered molecules of 2,2-bis(5-phenyl-1-,3,4-oxadiazol-2-yl)biphenyl has been studied. Crystals that are suitable for x-ray diffraction analysis can be obtained for the different conformers of this compound. It has been found that during synthesis the molecule of this compound is obtained in an energetically less favorable conformation. On the basis of model calculations using the AMI method with geometry optimization it has been proposed that during synthesis there are no changes in conformation of either the intermediates or the final product and the conformation of the resulting oxadiazole system is governed by the conformation of the initial 2,2-diphenic acid dichloride.Khar'kov State University, Khar'kov 310077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 984–991, July 1996. Original article submitted April 23, 1996.     

The crystal structure of gummosin

Summary The reaction of 3,3,5,7-tetraacetylquercetin with tetraacetylglucopyranosyl bromide has given quercetin 4-O--D-glucopyranoside, and the substance has been characterized.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–578, September–October, 1974.     

Acylation of steroid alcohols with 3-carboxypropanamido acids

Using N-(3-carboxypropanoyl)--phenyl--alanine as a model it has been established that when steroid alcohols are esterified with 3-carboxypropanamido acids, the carboxy group of the succinic acid residue takes part in the esterification reaction. In order to obtain a steroid ester of a 3-carboxypropanamido acid in which the carboxyl of the amino acid is the esterifying group, the carboxy group of the succinic acid residue must first be esterified.Khar'kov Scientific-Research Institute of Endocrinology and Hormone Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 700–704, September–October, 1985.     

Cardenolides of Erysimum suffruticosum

Conclusion Seven cardenolides have been isolated from the seeds ofErysium suffruticosum Spreng.: digitoxigenin, strophanthidin, erysimin, desglucocheirotoxin, desglucoerycordin, canescein, and a new glycoside which we have called bipindogulomethyloside. The latter is bipindogenin 3-O--D-gulomethyloside.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 178–183, March–April, 1974.     

New semisynthetic cardiac glycosides and their biological activity

Digitoxigenin, digitoxin, D-xylose and L-rhamnose have been used as the starting materials for the synthesis of the new cardiac glycosides: digitoxigenin 3-O--D-xylopyranoside and digitoxin 4-O--L-rhamnopyranoside. It has been established that the compounds obtained possess comparatively high biological activities.All-Union Scientific-Research Institute of Drug Chemistry and Technology. Khar'kov Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 776–779, November–December, 1990.     

4-Hydroxy-2-quinolones 19. A new synthesis of 3-Alkyl-2-oxo-4-hydroxyquinolines

3-Alkyl-substituted 2-oxo-4-hydroxyguinolines were obtained in high yields from N,N-di-2-alkoxycarbonylanilides of alkylmalonic acids under conditions of the Dieckmann condensation. Some types of biological activity were found for the compounds synthesized.For Communication 18, see [1].Ukrainian Pharmaceutical Academy, Khar'kov 310002. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 673–678, May, 1994. Original article submitted May 6, 1994.     

Cardiac glycosides of Cheiranthus allioni. XIII. Glucoerycordin

From plains erysimum (Cheiranthus allioni) Hort., (Erysimum asperum) a new cardiac glycoside has been isolated which has been called glucoerycordin. Its chemical structure has been established mainly by stepwise hydrolysis and the identification of the hydrolysis products. Glucoerycordin C₄₁H₆₄ O₁₉, mp 131–135°C, [] _D ²⁰ –22.2 ± 3° (c 0.65; methanol) is 3-[O--D-glucopyranosyl-(1 4)-O--D-glycopyranosyl-(1 4)-gulomethylopyranosyloxy]-14,19-dihydroxy-5, 14-card-20(22)-enolide.All-Union Scientific-Research Institute of Drug Chemistry and Technology, Khar'kov. Khar'kov State Pharmaceutical Institute. Translated from Khimiya Prirodnykh, No. 1, pp. 73–75, January–February, 1989.     

Isolation of a urease from watermelon seeds and the study of its properties

The enzyme urease has been isolated from the seeds of the watermelon of the Ogonek variety and has been characterized. The molecular weight of a rechromatographed sample of the enzyme has been determined as 480,000. The pH dependence of the activity of the urease and the kinetic parameters of the enzyme have been studied.All-Union Scientific-Research Institute of the Chemistry and Technology of Drugs, Khar'kov. Vitaminy Scientific-Production Amalgamation, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 624–628, September–October, 1983.     

Ornithogalin — A cardenolide glycoside from Ornithogalum magnum

Summary From the pods ofOrnithogalum magnum Krasch. et Schischk. we have isolated a new cardenolide glycoside which has been called ornithogalin, the structure of which may be given as 3-O--D-glucopyranosyl-14-hydroxycard-4,20 (22)-dienolide.Khar'kov Chemical and Pharmaceutical Scientific-Research Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 38–40, January, 1971.     

Cardiac glycosides of Cheiranthus allioni. VI

Summary Another two cardiac glycosides have been isolated from the seeds ofCheiranthus allioni Hort. It has also been established that in cheiroside A the D-glucose is attached at C₄ of the D-fucose. The second glycoside, which we have called glucoalliside, is new, and has the structure of bipindogenin 3-O-[O--D-glucopyranosyl-(1 » 4)--L-glucomethylopyranoside].For Communication V, see [2].Khar'kov Chemical and Pharmaceutical Scientific-Research Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–45, January, 1971.