Direct synthesis of 3-acylbenzothiophenes via the radical cyclization of 2-alkynylthioanisoles with α-oxocarboxylic acids.

A radical cascade cyclization of 2-alkynylthioanisoles with α-oxocarboxylic acids with AgNO3 has been described. This reaction provides a novel route to directly access 3-acylbenzothiophenes from simple chemical feedstocks. In particular, the utility of the approach was demonstrated by its application to the synthesis of a polymerization inhibitor and a raloxifene precursor.