Yu. É. Pelcher
Latvian Academy of Sciences
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Chemistry of Heterocyclic Compounds | 1987
A. A. Krauze; E. E. Liepin'sh; Yu. É. Pelcher; Z. A. Kalme; G. Ya. Dubur
Alkylation of piperidine salts of 6-hydroxy-4,6-diaryl-5-ethoxycarbonyl-3-cyanopiperidine-2(1H)-thiones yielded 6-hydroxy-2-alkylthio-4,6-diaryl-5-ethoxycarbonyl-3-cyano-3,4,5,6-tetrahydropyridines which were dehydrogenated with the formation of 2-methylthio-1,4- and 4,5-dihydropyridines. The oxidation of the compounds prepared has been studied.
Chemistry of Heterocyclic Compounds | 1987
A. A. Krauze; E. E. Liepin'sh; Yu. É. Pelcher; G. Ya. Dubur
The alkylation of piperidinium salts of substituted 1,4-dihydropyridine-2-thiols with chloroacetonitrile or iodoacetamide gave 2-cyanomethylthio- and 2-carbamoylmethylthio-substituted 6-methyl-4-aryl(pyridyl)-5-ethoxycarbonyl-3-cyano-1,4-dihydropyridines, which undergo intramolecular cyclization in basic media to give 3-amino-6-methyl-4-aryl(pyridyl)-5-ethoxycarbonyl-2-cyano(carbamoyl)-4,7-dihydrothieno[2,3-b]pyridines.
Chemistry of Heterocyclic Compounds | 1983
A. A. Krauze; Z. A. Kalme; Yu. É. Pelcher; E. E. Liepin'sh; I. V. Dipan; G. Ya. Dubur
Abstract3-Cyano-4, 6-diaryl-3, 4-dihydropyridine-2-thiones have been synthesized for the first time by the condensation of arylideneacetophenones or 1-piperidino-1-phenyl-2-benzoylethane with cyanothioacetamide and the 1, 1-dicyano-2-aryl-3-benzoylpropane with hydrogen sulfide in the presence of bases. It has been established by PMR spectroscopy that 3-cyano-3,4-dihydropyridine-2-thiones exist in solutions in the form of mixture of cis and trans isomers.
Chemistry of Heterocyclic Compounds | 1996
A. I. Ozols; Yu. É. Pelcher; Zenta Kalme; Yu. Yu. Popelis; Ivars Turovskis; G. Ya. Duburs
Abstract8-Aryl-7-acetyl-1, 6-dimethyl-6-hydroxy-4-cyano-5, 6, 7, 8-tetrahydro-3(2H)-isoquinolinones and -isoquinolinethiones and their sodium salts were obtained by the reaction of cyanoacetamide and cyanothioacetamide with 3-aryl-2, 4-diacetyl-5-methyl-5-hydroxycyclohexanonesinbasicrnedium. 8-Aryl-7-acetyl-6-methoxycarbonyl-1, 6-dimethyl-4-cyano-5, 6, 7, 8-tetrahydro-3(2H)-isoquinolinones were obtained by the reaction of acetyl chloride and the above isoquinolinone sodium salts. The reaction of iodoacetamide and the above isoquinolinethione sodium salts yielded 8-aryl-7-acetyl-3-carbamoylmethylthio-1, 6-dimethyl-4-cyano-5, 6, 7, 8-tetra-hydroisoquinolines, which were cyclized into 1-amino-6-aryl-7-acetyl-2-carbamoyl-5, 8-dimethyl-8-hydroxy-6, 7, 8, 9-tetrahydrothiophene[2,3-c]isoquinolines in basic medium.
Pharmaceutical Chemistry Journal | 1985
A. A. Krauze; R. O. Vitolinya; G. V. Zarin'sh; Yu. É. Pelcher; Z. A. Kalme; A. A. Kimenis; G. Ya. Dubur
H H Ia-g , Ila-f I l la-f Ia-g:R i = H, R s ---Phi lla-d, I:R i = = C O O E r , R ~ = Me; IIe R 1 = COObte, R s = Me; Ia:R = H; IbfR = OCHFs-o; ~:R = F-o; Id~R = F@; I~:R = NO~.m; I~R = N@9~; I~:R = Br-~ I Ia :R~ H; ~b:R = NO~.m; IIq.R = NO~-p; IId, e,R = =CI-P; IIe:R = OMe-P; I l la ,b;R1 = Me; IIIr l = p h ; IIIa:R=Me; I I I b , c : R = =Ph; I I Id :R= C~H4OCHF2-o; IIIe:R = =C6HINO2-~ III~R=C6H4CI-p.
Chemistry of Heterocyclic Compounds | 1984
A. A. Krauze; . . Liepin'sh; Z. A. Kalme; Yu. É. Pelcher; G. Ya. Dubur
The condensation of benzylideneacetonacetic ester with cyanoacetamide in the presence of triethylamine yielded 3-carbamoyl-3,4-dihydropyridin-2-one, while the condensation of arylidenecyanoacetamides with β-aminocrotonic ester in acetic acid yielded 3-cyano-3,4-dihydropyridin-2-ones. It was established by NMR spectroscopy that 3-cyano-4-R-5-ethoxycarbonyl-6-methyl-3,4-dihydropyridin-2-ones exist in solutions in the form of a mixture of cis- and trans-stereoisomers in a 10∶1 ratio.
Chemistry of Heterocyclic Compounds | 1976
Z. A. Bomika; M. B. Andaburskaya; Yu. É. Pelcher; G. Ya. Dubur
The chlorine atom in 2-chloro-3-cyanopyridines is readily replaced by primary and secondary aliphatic amines and heterocyclic amines to give 2-aminopyridines. 2-Chloro-3-cyanopyridines react with hydrazine hydrate and sodium azide to give hydrazinopyridines, pyridopyrazoles, azidopyridines, and pyridotetrazoles.
Chemistry of Heterocyclic Compounds | 1975
Z. A. Bomika; M. B. Andaburskaya; Yu. É. Pelcher; G. Ya. Dubur
On the basis of IR, UV, and PMR spectra it was established that, depending on the starting compounds and the reaction conditions, 1,2-dihydro-2-oxopyridine and 1,2,3,4-tetrahydroand 2, 3, 4, 5-tetrahydro-2-oxopyridine derivatives are obtained by condensation of malondiamide or cyanacetamide with α, β-unsaturated mono-ketones (benzylideneacetophenone, benzylideneacetone, and mesityl oxide).
Chemistry of Heterocyclic Compounds | 1992
Z. A. Kalme; B. Roloff; Yu. É. Pelcher; Yu. Yu. Popelis; F. Khagen; G. Ya. Dubur
Methods of synthesis of 5-carbomethoxy-substituted pyrazolo[3,4-b]pyridines and 3H-imidazo[4,5-b]pyridines by their reaction with hydrazine hydrate or as a result of Hofmann rearrangement of the corresponding 2-aminopyridines were developed based on 4-aryl-3-carbamoyl(or cyano)-5-carbomethoxy-6-methyl-2-chloropyridines.
Chemistry of Heterocyclic Compounds | 1992
Z. A. Kalme; B. Roloff; Yu. É. Pelcher; Yu. Yu. Popelis; F. Khagen; G. Ya. Dubur
Abstract3-Cyano- and 3-carbamoyl-2-chloropyridines react with hydrazine hydrate to form substituted 3-amino-1H-pyrazolo[3,4-b]pyridines and 3-oxo-2,3-dihydro-1H-pyrazolo[3,4-b]pyridines. Hydrazine hydrate reacts with 3-carbamoyl-2-chloro-5-oxo-5,7-dihydrofuro[3,4-b]pyridine to form substituted 3,5-dioxo-2,3,5,7-tetrahydro-1H-pyrazolo[3,4-b]furo[3,4-e]pyridine.