Studies with functionally substituted enamines: Synthesis of new aminoazolo-pyrimidines and -1,2,4-triazines

Abstract

3-Aminoacrylonitrile derivatives (1d-g) coupled with aromatic and heteroaromatic diazonium salts yielding arylhydrazonals and pyrazolo[5,1-c] triazines. The enaminonitriles 1d-g condensed to form dienes 6a-c on reflux in acetic acid. The latter underwent Diels-Alder type addition to naphthoquinone. Aminopyrazolopyrimidines were obtained from reaction of 1d-g with heteroaromatic aminoazoles. Enaminonitrile 1d formed pyran 21 with benzylidenemalononitrile, and dihydropyrimidine 22 with benzaldehyde and urea.