To a stirred mixture of lithium aluminum hydride (0.152 g, 4.00 mmol,2 eq) in anhydrous tetrahydrofuran (10 mL) at 0° C. was added rapidly a solution of the 3-(N-benzyloxycarbonylpyrrolidin-2-ylmethyl)-1H-indole or the 3-(N-benzyloxycarbonylpiperid-2-ylmethyl)-1H-indole (2.00 mmol) in anhydrous tetrahydrofuran (5 mL). The resulting mixture is heated at reflux under a nitrogen atmosphere for 3 hours. The reaction mixture is cooled, and water (0.25 mL), 15% aqueous sodium hydroxide (0.25 mL), and then more water (0.75 mL) were added sequentially. The resulting mixture was stirred at 25° C. for 30 minutes, filtered, and the filtrate was evaporated under reduced pressure. The residue was column chromatographed using silica gel (approximately 50 g) and solution with a solution methylene chloride: methanol: ammonium hydroxide [9:1:0.1] or other appropriate solvent system to afford the corresponding 3-(N-methylpyrrolidin-2-ylmethyl)-1H-indole or 3-(N-methylpiperid-2-ylmethyl)-1H-indole.
