Two directions in the heterocyclization of thiocarbamoylpyridinium(isoquinolinium)ylides in their interaction with esters of acetylenecarboxylic acids

Research paper by V. S. Berseneva, N. Yu. Biryucheva, V. A. Bakulev

Indexed on: 01 Dec '93Published on: 01 Dec '93Published in: Chemistry of Heterocyclic Compounds


It has been found that pyridinium- and isoquinoliniumthiocarbamoylazomethinylides react with esters of acetylenedicarboxylic and propiolic acids in two directions. The first direction is heterocyclization of the thioamide fragment of the ylide; under the influence of dimethyl acetylenedicarboxylate, a thiazolyl-4-one ring is formed, and by the interaction of the pyridiniumylide with methyl propiolate, a thiazin-4-one ring is formed. The second direction consists of annelation of the imidazole ring to the isoquinoline system upon reaction with methyl propiolate.