Novel Cyclization of S-(o-Acetylaryl) Dimethylthiocarbamates. A New Synthesis of 3-Hydroxybenzothiophenes and 2-Hydroxythiochromones

Article abstract of DOI:10.1021/jo00385a005

The rearrangement of O-(o-acetylaryl) dimethylthiocarbamates to their corresponding S-aryl dimethylthiocarbamates, previously reported to be a very low yielding reaction, have been achieved in acceptable yields.The versatility of these intermediates is demonstrated by their transformation into different heterocyclic systems.Thus, when the resulting S-(acetylaryl) dimethylthiocarbamates are treated with base in the presence of air, they cyclize in a novel fashio to yield substituted N,N-dimethyl-3-hydroxybenzothiophene-2-carboxamides and substituted 2-hydroxythiochromones.In the absence of air, only the latter was formed.