Syntheses of di-heterocyclic compounds; pyrazolylimidazoles and isoxazolylimidazoles

Fifteen substituted di-heterocyclic imidazoles were prepared. Ten substituted pyrazolylimidazoles were obtained by cyclocondensation of α-oxo-α-imidazolylketene dithioacetal or N, S-acetals with hydrazine and by ring-chain transformation of cyclic α-oxo-α-imidazolylketene N, O-acetals. Five isoxazolylimidazoles were obtained by reaction of α-oxo-α-imidazolylketene dithioacetal with hydroxylamine. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:317–320, 1998