A series of 4-amino-5-chloro-2-methoxy-N-(piperidin-4-ylmethyl) benzamide derivatives bearing an aralkylamino, alkylamino, benzoyl or phenylsulfonyl group at its side chain part at the 1-position on the piperidine ring was synthesized. They were evaluated for serotonin 4 (5-HT4) receptor agonist activity by testing their ability to contract the isolated guinea-pig ascending colon. 4-Amino-5-chloro-2-methoxy-N-[1-[5-(1-methylindol-3-ylcarbonylamino) ...