Ring opening-ring closure of 4-phenyl-1,2-dithiole-3-thione:convenient route to novel thiinethione derivatives by the reaction with active methylene nitriles

摘要

4-Phenyl-1,2-dithiole-3-thione (1) reacts with active methylene nitriles in the presence of triethylamine to afford fused and isolated thiine derivatives, mainly from initial nucleophilic attack of methylene group at C-5 of the dithiole ring.