Pharmacologically active benzo[b]thiophen derivatives. Part IX. Some 4- and 5-monosubstituted and 4,5-disubstituted amines and thiouronium salts

Abstract

Ethyl 5-amino-3-methylbenzo[b]thiophen-2-carboxylate was converted by standard methods into ethyl 3-methylbenzo[b]thiophen-2-carboxylate and its 4-bromo-, 5-bromo-, and 4,5-dibromo-derivatives.

5-Amino-3-methylbenzo[b]thiophen was similarly converted into 5-cyano-, 5-carboxy-, and 5-ethoxycarbonyl-3-methylbenzo[b]thiophen.

These 3-methylbenzo[b]thiophen derivatives were brominated with N-bromosuccinimide in boiling carbon tetrachloride, and some of the resulting 3-bromomethyl compounds were treated with thiourea or substituted thioureas to give a number of substituted S-2-ethoxycarbonyl-3-benzo[b]thenylthiouronium bromides. Other bromomethyl compounds reacted with diethylamine, morpholine, or pyrrolidine to give the corresponding tertiary amines, or with N-alkylethanolamines to give substituted 2-hydroxyethylamines, which gave the corresponding 2-chloroethylamines when treated with thionyl chloride in boiling chloroform. The results of a preliminary pharmacological study of these compounds are included.