Heterocycles containing a bridge nitrogen atom. 10. Unexpected closure of oxazole ring during the reaction of 2-chloro-1-phenacylpyridinium salt with potassium cyanate. Crystal structure of 2-(p-nitrophenyl)oxazolo-[3,2-a]pyridinium bromide and N-(p-nitrophenacyl)pyrid-2-one

Abstract

Reaction of 2-chloro-N-(p-nitrophenacyl)pyridinium bromide with potassium cyanate in acetonitrile produces 2-(p-nitrophenyl)oxazolopyridinium bromide. Performing the same reaction in methanol N-(p-nitrophenacyl)pyrid-2-one was isolated. The structures of the obtained products were proved by X-ray structural data.