Popil'nichenko S. Heterocyclizations of beta-chloro substituted enamidonitriles with N- and S-nucleophiles

The dissertation is dedicated the research on the heterocyclizations of beta-chloro substituted enamidonitriles which proved to be applicable for preparative syntheses of a large number of functionalized thiophenes, pyrazoles, imidazoles, pyrimidines, pyrazolo[1,5 a]pyrimidines, thieno[3,2-d]pyrimidines, thieno[2,3-b][1,4]thiazines, and other fused systems. All these diverse conversions can be classed as first-type or second-type processes by the behaviour of the acylamino groups of enamidonitriles. First-type cyclocondensations occur in the reaction of beta-chloro substituted enamidonitriles with hydrazine hydrate to provide 3(5)-amino-4-acyl-aminopyrazoles which readily condense with ? dicarbonyl compounds to the corresponding 3-acylaminopyrazolo-[1,5-а]pyrimidines. The cyclocondensation of 2-acylamino-3-chloroacrylonitriles with 2-aminopyridine proceeds peculiarly, with the elimination of cyanhydric acid, to furnish 2-acylaminoimidazo[1,2-a]pyridines. Sphere of use - organic chemistry.