Synthesis and biological screening of 3-chloro-2-piperazinylmethyl-N-aryl sulfonamide indole derivatives as 5-HT6 receptor ligands: Part III

In continuation to our earlier work and to improve upon the potentency of 2-piperazinylmethyl-N-aryl sulfonamide indole derivatives, a new series of compounds were taken up for synthesis by inserting halo group at 3rd position of indole. The critical intermediate 3-halo-2-formyl indole was achieved through the Vilsmerier reaction, which on further reductive amination followed by sulfonylation gave 3-chloro-2-piperazinylmethyl-N-aryl sulfonamide indole derivatives as a targeted series of compounds. The design, synthesis and their in-vitro affinity towards the 5-HT6 receptor is discussed in this communication.