New 3-[4-(2,3-dihydro-14-benzodioxin-5-yl)piperazin-1-yl]-1-(5-substituted benzo[b]thiophen-3-yl)propanol derivatives with dual action at 5-HT(1A) serotonin receptors and serotonin transporter as a new class of antidepressants

Compounds derived from 2,3-dihydro-(1,4-benzodioxin-5-yl)piperazine and benzo[b]thiophene with different substituents in 5 position (H, F, NO2, NH2, CH3 and OH) have been synthesized in order to obtain new dual antidepressant drugs. The final compounds were evaluated for in vitro 5-HT(1A) receptor affinity and serotonin reuptake inhibition by radioligand assays. Compounds 1-(5-nitrobenzo[b]thiophen-3-yl)-3-[4-(2,3-dihydro-1,4-benzodioxin-5-yl)piperazin-1-yl]propan-1-ol (4c) (Ki = 6.8 for 5-HT(1A) receptor and Ki = 14 for 5-HT transporter) and 1-(5-hydroxybenzo[b]thiophen-3-yl)-3-[4-(2,3-dihydro-1,4-benzodioxin-5-yl)piperazin-1-yl] propan-1-ol (4f) (Ki = 6.2 for 5-HT(1A) receptor and Ki = 18.2 for 5-HT transporter) showed the best results for both activities.