[en] A number of ethyl esters of 3,3-dialkyl-3,4-dihydroisoquinoline-Δ¹/sup (2H),α/-α-alkylacetic acids have been synthesized. The effect of replacement of α-hydrogen by alkyl radicals on the azomethine-enamine tautomeric equilibrium was shown

[en] A preparative method has been developed for obtaining substituted nitrotryptamines from the corresponding nitrophenylhydrazones of Υ-phthalimidobutyraldehyde

[en] The reaction of 1-phenyl-3-(3,4-dimethoxyphenyl)-3-(2-oxocyclohexyl)-1-propanone with hydrogen sulfide and acids gives an intramolecular rearrangement product, 2α-phenyl-2,4-ortho-(14,15-dimethoxybenzo)-cis-1-thiadecalin in addition to the usual products of disproportionation of intermediate 2-phenyl-4-(3,4-dimethoxyphenyl)-5,6-tetramethylene-4H-thiopyran, namely, 5,6-tetramethylenethio-pyrilium salts and 2α-phenyl-4α-(3,4-dimethoxyphenyl)-cis-1-thiadecalin. The configurational and conformational assignments for the sulfides, their sulfoxides, and sulfones were made by ¹³C NMR spectroscopy

[en] The corresponding 5-mono- and 5,7-disubstituted 6-oxo-1,3-diazaadamantanes were obtained with high yields by the condensation of mono- and α,α'-disubstituted acetones with hexamethylenetetramine in the presence of glacial acetic acid, and their structures were confirmed by IR and PMR spectra. The behavior of the compounds under electron impact was studied, and the main fragmentation paths of their molecules were determined

[en] 2-β-D-Ribofuranosyl-4-methylthio-5-methoxycarbonyl-1,2,3-triazole was obtained by fusing 4-methylthio-5-methoxycarbonyl-1,2,3-triazole together with tetraacyl-D-ribofuranose, followed by deacylation, and its amide and hydrazide were prepared. The structures of the new nucleosides were established by converting them into known 2-nucleosides of 1,2,3-triazol-4-yl-carboxylic acid derivatives. By comparing PMR spectra with previously reported PMR spectra for the isomeric 1- and 2-nucleosides of 1,2,3-triazol-4-yl-carboxylic acid derivatives, the synthesized nucleosides could be assigned to 2-substituted triazoles

[en] It was shown by means of ¹H and ¹³C NMR spectroscopy that the reaction of 2-arylmethylene-3-oxoquinuclidines with hydrazine hydrate gives 4a-hydroxy-7-aryl-4a,5,7,7a-tetrahydropyrazolo[4,3-b]quinuclidines, which are stable in the crystalline state but undergo dehydration to the corresponding 7-aryl-6H-7,7a-dihydropyrazolo[4,3-b]quinuclidines in solutions. The latter undergo cleavage to 3-(4-piperidyl)-5-arylpyrazoles when they are heated in an alkaline medium

[en] As a consequence of partial double bond nature of the exocyclic C-N bond, 2-methyl-amino-4-thiazolinone exists in DMSO-D₆ as a mixture of E and Z conformers of the amino form with predominance of the sterically favored E conformer. 2-Phenylimino-4-thiazolidinone in the same solvent exists as a mixture of the E and Z isomers of the imino form

[en] The existence of several sites of charge localization upon the mass spectrometric decomposition of stereoisomeric 3-hydroxy-4-piperidones leads to a large number of fragmentation products both with retention and destruction of the piperidine ring. Analysis of the mass spectra of the compounds studied showed that the appearance of [M - CO]⁺ ion peaks for isomers with an axial hydroxyl group may serve as a method for determining the configuration of the carbinol site of such cyclic structures

[en] Benzodioxane analogs of chalcones and their epoxides have been prepared. Different types of analogs of natural flavonolignan - silibin - have been synthesized from these compounds. The PMR spectra of the new compounds and the results of the preliminary biological testings are reported and discussed

[en] The chemical shift of the carbon atom of the nitrone group in the ¹³C NMR spectra of 3-imidazoline 3-oxides lies in the region of 117-152 ppm and depends on the electronic effect of the substituents at positions 1, 4, and 5 of the heterocycle. Increase in the electron-withdrawing character of the substituent at these positions leads to an upfield shift of the signal for the nitrone carbon atom, and this corresponds to the increase in electron density on it