Reactions of tetrahydropyrido[4,5-d][1,2,4]triazolo[1,5-a]-pyrimidin-4-ones with activated alkynes. Synthesis of [1,2,4]triazolo[1′,5′:1,2]pyrimido[4,5-d]azocines
作者:L. G. Voskressensky、T. N. Borisova、M. V. Ovcharov、E. A. Sorokina、V. N. Khrustalev、A. V. Varlamov
DOI:10.1007/s11172-012-0213-4
日期:2012.8
Triazolo[1′,5′:1,2]pyrimido[4,5-d]azocines were synthesized by the tandem expansion of the tetrahydropyridine ring in tetrahydropyridotriazolopyrimidines by the action of activated alkynes. Under these conditions, triazolopyridopyrimidines benzylated at the nitrogen atom of the pyrimidine moiety undergo the Hofmann cleavage of the tetrahydropyridine ring to form 5-vinyltriazolo[1,5-a]pyrimidines.
Tautomerism of Aza cycles: IV. Tautomeric structure of 4,5-dihydropyrazol-5-one annelated on bond C3-C4 with piperidine cycle, and its three hydrochlorides
作者:B. I. Buzykin、A. T. Gubaidullin、V. N. Nabiullin、A. F. Saifina
DOI:10.1134/s1070363214030219
日期:2014.3
5-Methyl-2-phenyl-3,3a,4,5,6,7-hexahydro-2H-pyrazolo[4,3-c]pyridin-3-one has been synthesized and shown to exist in crystal as zwitterionic structure with the proton localized on the nitrogen atom in the piperidine ring and negative charge delocalized over the pyrazololate fragment. The structure of 2: 1, 1: 2, and 2: 3 hydrochlorides derived from the title compound has been determined by X-ray analysis.
Maurit; Preobrashenskii, Zhurnal Obshchei Khimii, 1958, vol. 28, p. 968,972; engl. Ausg. S. 943, 946