Synthesis of 11-14C-quetiapine, 11-14C-isoclotiapine and 10-(4-methylpiperazin-1-yl)pyrido[4,3-b][1,4]benzothiazepine[10-14C]

Quetiapine is one of the most widely used antipsychotic drug which acts as an antagonist for multiple neurotransmitter receptor sites. 2-[2-(4-(Dibenzo[b,f][1,4]thiazepin-11-yl)piperazin-1-yl)ethoxy]ethanol (quetiapine) labeled with carbon-14 in 11-position has been synthesized as part of a 5-step sequence from anthranilic acid-[carboxy-C-14]. We have presented a convenient synthetic pathway for labeling of quetiapine with carbon-14 by using one-pot procedures from a key thiazepin-11(10H)-one-[11-C-14] by good radiochemical yield. And also isoclotiapine[11-C-14], and 10-(4-methylpiperazin-1-yl)pyrido[4,3-b][1,4]benzothiazepine[10-C-14], synthesized according to this route.