The Chemistry of 5-Oxodihydroisoxazoles. XXI Amidines and Pyrimidin-4-ones from the Reaction of Isoxazol-5(2H)-ones with Amines

Abstract

While isoxazol-5(2H)-ones substituted with heterocycles at C2 but unsubstituted at C3 react with amines to give either amidines or malonamides, their reaction at low temperatures with lithium dialkylamides is a preparatively useful procedure for obtaining the amidines in most cases. Longer reaction times may lead to formation of pyrimidin-4-ones when ester groups are present at C4 of the isoxazolone.