Synthesis of novel N-benzyl substituted piperidine amides of 1H-indole-5-carboxylic acid as potential inhibitors of cholinesterases

A series of novel N-benzyl substituted amides of 1H-indole-5-carboxylic acid were synthesized and evaluated for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The target compounds (6b-6e) displayed moderate potency to inhibit BuChE. One of the compounds tested, i.e., 1-benzylpiperidine amide of 1H-indole-5-carboxylic acid (6a) was a weak, non-selective inhibitor for both enzymes. The highest inhibitory activity towards BuChE (30.06% [10 microM]) was determined for compound (6c) which is 1-(3-chloro)benzylpiperidine amide of 1H-indole-5-carboxylic acid.