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 benzylidene malononitrile, and dihydropyrimidine 22 with benzaldehyde and urea.