PROCESS FOR THE PREPARATION OF BENZOTHIOPHENE DERIVATIVES

摘要

The present invention is concerned with a novel process for the preparation of the hydroxybenzothiophene of Formula I (see formula I) comprising cyclocarbonylation of a compound of Formula II (see formula II) wherein -OR is as defined in the specification, followed by saponification. The compound of Formula I is a building block of pharmaceutically active substances, e.g. 5- [4-[2-(5- methyl-2-phenyl-4-oxazolyl)ethoxy]-7-benzothiophenylmethyl]-2,4- thiazolidinedione and the corresponding sodium salt.