SYNTHESIS OF NEW CONJUGATED MESOMERIC BETAINES FROM ALKOXYCARBONYLAZINIUM SALTS

A new series of conjugated mesomeric betaines have been synthesized Fr om the reaction of various aminoheterocycles with lthio-4-oxo-3-phenyl pyrido[2.1-f][1,2,4]triazinium iodide, itself prepared from 2-ethoxyca rbonylpyridinium N-aminide. Some of the heterobetaines and sails obtai ned have been studied by H-1-NMR. and their structures have been confi rmed by X-ray. analysis The crystal structures reveal unexpected compl ementary stabilizing interactions between some betaines and their salt s. Copyright (C) 1996 Published by Elsevier Science Ltd