Synthesis of 2-alkyl-3-(2-benzoxazolon-3-yl)indoles

It was shown that 3-(2-oxoalkyl)-2-benzoxazolones with phenylhydrazine in the presence of polyphosphoric acid form the corresponding 2-alkyl-3-(2-benzoxazolon-3-yl)-indoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1087, August, 1984.     

Stereochemistry of sesquiterpenes of the germacrane type

An analysis has been made of the conformations of the 10-membered ring in the known sesquiterpene E,E-germacranes and a relationship has been established between the realization of one of the four conformers and the positions and orientations of substituents in the 10-membered ring. A relationship is presented between the conformational states of the germacrolides and the structures of their bicyclic derivatives — guaianes and eudesmanes.Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 497–506, July–August, 1997.     

2,6-di-tert-butyl-4-perimidylphenols and their oxidation

1,8-Naphthylenediamine was reacted with 2,6-di-tert-butyl-4-formyl-phenol to produce 2,6-di-tert-butyl-4-(1,3-dihydro-perimidyl) phenol (I). The latter was coverted into 2,6-di-tert-butyl-4-(1H-perimidyl)phenol (II) by oxidizing I with sodium pyrosulfate. When phenol II was oxidized by lead dioxide in toluene and THF, the EPR spectra revealed a 12-component multiplet with perimidyl splitting constants a¹ _N=a³ _N=a_H ^NH=0.2 mT; a_H ^6.7=0.6 mT.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 1, pp. 64–67, January, 1992.     

Study of the absorption spectra and ionic equilibria of cationic-anionic polymethine dyes

The absorption spectra of a number of cationic-anionic polymethine dyes in polar, low-polarity, and nonpolar solvents were studied. It was established that in polar solvents the absorption spectra represent the sum of the absorption spectra of the cation and anion, whereas in nonpolar and low-polarity solvents, in many cases the appearance of a short-wave absorption band is observed, due to interaction of the chromophores of the cation and anion in ion pairs. In solvents of intermediate polarity (for example, in chloroform and ethyl acetate), a concentration dependence of the absorption spectra is observed, determined by the equilibria of ionic dissociation. The ionic dissociation constants of a number of cationic-anionic dyes in chloroform and ethyl acetate were determined by a conductometric method. The thermodynamic data obtained are compared with the spectral data.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2524–2532, November, 1992.     

Phosphorylation of lignins I. Phosphorylation of piperidinomethylated dioxane lignin from cottonseed husks

The phosphorylation of piperidinomethylated dioxane lignin has been studied. It has been shown that the reaction takes place with the formation of quaternary ammonium phosphates, while the transesterification of dimethyl phosphite with an aliphatic hydroxy group of the lignin is also possible.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 275–277, March–April, 1993.     

Phospholipids of kenaf of variety Opytnyi-1847

The total phospholipids of kenaf of variety Opytnyi-1847 and homogeneous fractions of them have been studied. A known law has been confirmed — positions 2 of the main fractions of phospholipids are esterified predominantly with unsaturated fatty acids and in N-aceylated phospholipids the amide-bound acids are more saturated than the O-acyls.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 775–777, November–December, 1980.     

Nitrobenzene oxidation of fractions of cotton-plant dioxane lignin

Summary Analysis of the products of alkaline nitrobenzene oxidation of lignin fractions has confirmed their chemical inhomogeneity and has shown that in the various fractions the amounts of condensed syringly and guaiacyl structures differed markedly.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii No. 1, pp. 82–84, January–February, 1979.     

Free radicals in electrochemical reduction of 3,5-dicarbethoxy-1,4-dihydropyridines with nitrophenyl groups in positions 2, 4, and 6

In the electrochemical reduction of 2,6-bis- and 2,4,6-tris(nitrophenyl) derivatives of 3,5-dicarbethoxy-1,4-dihydropyridine, in the first stage, one of the para-nitrophenyl groups in position 2 or 6 of the heterocycle is reduced. Free radicals have been obtained and identified, the primary species being ion radicals of the nitrophenyl type. The presence of the heterocycle in the molecule of the 1,4-dihydropyridine derivative stabilizes secondary free radicals of the nitrosophenyl type. In the process of electrochemical reduction, no evidence has been found of any intramolecular transfer of electrons or protons from the dihydropyridine part of the molecule to the nitrophenyl groups. Derivatives of 2,6-bis(p-nitrophenyl)-3,5-dicarbethoxy-1,4-dihydropyridine have been synthesized, and the oxidation and methylation of these derivatives have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 481–487, April, 1991.     

Alkaloids ofThalictrum isopyroides

Summary 6,7-Dimethoxy-2-methyl-1,2-dihydroisoquinolin-1-one and the new aporphine base 9-hydroxy-1,2,3,10-tetramethoxyaporphine, which has been called thalisopynine, have been isolated fromThalictrum for the first time.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnyk Soedinenii, No. 4, pp. 472–474, July–August, 1978.     

Minor phospholipids of the seeds of the cotton plant of variety “Tashkent-2” structure of the N-acyllysophosphatidylethanolamine

Summary The minor phospholipids from the seeds of the cotton plant of variety Tashkent-2 have been isolated and studied. It has been established that the FA's attached to the N atom are more saturated than the corresponding O-acyls. For the N-acyllsyo-PE the structure of a 2-acylglycerophosphoryl-N-acylethanolamine has been proposed. As in the main fractions, in the minor components of the phospholipids of the seeds of the cotton plant of variety Tashkent-2 the saturated fatty acids mainly occupy position 2.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedininii, No. 1, pp. 41–44, January–February, 1978.