Synthesis and chemical reactivity of 3-oxo-2-arylhydrazono-propanenitriles

2-Formyl-2-arylhydrazonoethanenitiiles 6b-d where prepared via reacting enaminonitrile 2b,c with aromatic diazonium salts. These reacted with phenylhydrazine to yield his hydrazones that were converted to arylazopyrazoles via a novel Vilsmeier-Haack reaction type. Reaction of 6c with hydroxylamine afforded oxime that could be successfully cyclised into arylazoisoxazole. Reaction of 6c with hydrazine hydrate to yield arylazoaminopyrazole that proved to be excellent precursors for synthesis functional substituted pyrazolopyrimidines.