Synthesis of new 5-substitutedbenzo[b]thiophene derivatives

Previous works of our group have dealt with the synthesis of 1-(aryl)-3-[4- (aryl)piperazin-1-yl]propane derivatives in the search for new and efficien t antidepressants with a dual mode of action: serotonin reuptake inhibition and 5-HT1A receptor afinity [1-4]. From these studies we concluded that th e 3-[4-(aryl)piperazin-1-yl]-1-(benzo[b]thiophen-3-yl)propane derivatives l ed to the best results. The continuation of this research project required the preparation of some new 3-acyl-5-substituted benzo[b]thiophenes with a wide variety of substituents at the 5 position, ranging from nitro to hydro xyl derivatives. To obtain these derivatives we acylated the corresponding 5-substituted benzo[b]thiophenes when it was possible.