THE HEAT-CONDENSATION REACTION OF THIOPHTHALIDE AND THE RELATED COMPOUNDS

Heat-condensation reaction of Phthalic Anhydride (1a) with Phthalide (2a) or the corresponding sulfur compounds (1b), (2b) were investigated.The products were not only Biphthalide type compounds (3), but also much a condensed cyclic type isomer (4).The yield and ratio of products were remarkably changed by the combination of sample and reacted condition.