Utility of Cyanoacetamides as Precursors to Pyrazolo[3,4-d]pyrimidin-4-ones, 2-Aryl-6-substituted 1,2,3 Triazolo[4,5-d]pyrimidines and Pyrazolo[1,5-a]pyrimidine-3-carboxamides

Abstract

Cyanoacetamides (7a-c) were prepared via reacting cyanoacetic acid (5) with amines in the presence of acetic anhydride.Compounds (7a-c) coupled with benzenediazonium chloride to yield the phenylhydrazones (8a-c).These reacted with chloroacetonitrile to yield aminopyrazolecarboxamides (11a-c).Reaction of (8a,b) with hydroxylamine hydrochloride in DMF in presence of anhydrous sodium acetate afforded the amino-1,2,3-triazolecarboxamides (36a,b).Also compounds (7a-c) reacted with dimethylformamide dimethylacetal (DMFDMA) to yield the enamines (9a-c) which react with hydrazine hydrate to afford the aminopyrazoles (16a-c).Compounds ( 16) and (36) reacted with DMFDMA to yield the title heterocyclic derivatives.