Heterocycles of biological importance. Part 1. Novel synthesis and biological activity study of 5‐Alkyl and 5‐Aryl‐7‐aminopyrazolo[1,5‐a]‐pyrimidines from allenic or acetylenic nitriles and 3‐aminopyrazole

Abstract
Allenic nitriles react with 3‐aminopyrazole in ethanol or dimethylformamide to give 5‐alkyl‐7‐aminopyrazolo[1,5‐a]pyrimidines5of pharmaceutical interest in good yields. 3‐Phenylpropynenitrile reacts with 3‐aminopyrazole in a similar manner to give the aryl compound8.