Cycloaddition of dimethyl acetylenedicarboxylate with 2-imino-1,3-oxathioles
Abstract
2-Phenylimino-1,3-oxathioles (1), acting as masked 1,3-dipoles with carbon as the central atom, add dimethyl acetylenedicarboxylate to give aryl propionitriles (4) and dimethyl 2,3-dihydro-3-phenyl-2-oxothiazole-4,5-dicarboxylate (3), probably as a result of thermal decomposition of a 1:1 cycloadduct (2).