Preparation of 3-imino-2-en-1-ones from 2-aralkylisoxazolium salts

Abstract

Isoxazolium salts having an aralkyl group on the nitrogen atom, such as 2-benzhydryl- and 2-fluoren-9-yl-isoxazolium salts, are decomposed by base to give the corresponding 3-imino-2-en-1-ones, while 2-methyl-3,5-diphenylisoxazolium perchlorate gives 4,6-diphenyl-2H-1,3-oxazine. The chemical behaviour of these 3imino-2-en-1-ones and the mechanism of their formation are also discussed.