Partially fluorinated heterocyclic compounds. Part II. The preparation of 4,5,6,7-tetrafluorobenzo[b]thiophen by a new cyclisation reaction
Abstract
The reaction of the pentafluorobenzenethiolate ion with ethyl acetylenedicarboxylate gave a derivative of 4,5,6,7-tetrafluorobenzo[b]thiophen by a new, one-step cyclisation reaction. Other synthetic approaches to this ring system by conventional cyclisation reactions are presented.