Pharmacologically active benzo[b]thiophen derivatives. Part VIII. Benzo[b]thiophen analogues of tryptophan and α-methyltryptophan, and some of their 5-substituted derivatives

Abstract

α-Amino-β-(3-benzo[b]thienyl) propionic acid, the benzo[b]thiophen analogue of tryptophan, has been prepared by reaction of 3-chloromethylbenzo[b]thiophen with diethyl acetamidomalonate or diethyl formamidoalonate, and acidic or alkaline hydrolysis of the product. Its 5-bromo-, 5-chloro-, 5-methyl-, and 5-nitro-derivatives were similarly preprared for pharmacologicl evaluation. (3-Benzo[b]thienyl)acetone, prepared by reaction of 3-benzo-[b]thienylacetyl chloride with diethyl ethozxymagnesium-malonate and acidic hydrolysis of the product, reacted with a mixture of potassium cyanide, ammonium chloride, and ammonium carbonate in aqueous ethanol to give 5-(3-benzo[b]thenyl)-5-methylhydantion alkaline hydrolysis of which gave the benzo[b]thiophen analogue of α-methyltryptophan. Its 5-bromo-, 5-chloro-, 5-methyl-, and 5-nitro-derivatives were prepared similarly.