Pharmacologically active benzo[b]thiophen derivatives. Part IV. 5- and 6-Alkyl derivatives with an N-alkyl-N-(2-chloroethyl)aminomethyl group in the 3-position

Abstract

3-Chloromethylbenzo[b]thiophen reacted with N-ethyl-, N-isopropyl-, N-butyl-, N-t-butyl, or N-benzyl-ethanolamine to give the corresponding N-alkyl-N-(2-hydroxyethyl)-3-aminomethylbenzo[b]thiophen derivatives. With thionyl chloride in dry chloroform these amino-alcohols gave the corresponding N-alkyl-N-(2-chloroethyl)-3-aminomethylbenzo[b]thiophen hydrochlorides. A similar range of compounds was obtained from 5- or 6-methyl-benzo[b]thiophen but only the N-ethyl derivative was prepared from 5-ethyl-, 5-isopropyl-, or 5-t-butyl-benzo[b]thiophen. NN-Di-(2-hydroxyethyl)-3-aminomethylbenzo[b]thiophen and its 5-ethyl derivative were also prepared and converted into the corresponding nitrogen mustards. These compounds have been evaluated pharmacologically, with special emphasis on their anti-5HT and anti-tumour activity.