76981-71-0 BRN 4183342 Benzo(b)thiophene-3-carboxylic acid, 4,5,6,7-tetrahydro-2-amino-6-methyl-, ethyl ester Ethyl 4,5,6,7-tetrahydro-2-amino-6-methylbenzo(b)thiophene-3-carboxylate