Methyl indole-6-carboxylate → Methyl indoline-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

NaCNBH3 (11.49 g; 0.04 equiv.) was added at 0° C., over a period of 10 minutes, to a solution of methyl 1H-indole-6-carboxylate (8 g; 1 equiv.) in acetic acid (80 ml). The reaction mixture was stirred at 0° C. for 20 minutes and then warmed to room temperature and stirred for 1 hour at room temperature. When the conversion was complete, the acetic acid was distilled off under reduced pressure and the resulting residue was dissolved in dichloromethane. The resulting phases were separated. The organic phase was washed with 1N sodium hydroxide solution and dried over sodium sulfate. After removal of the solvent under reduced pressure, purification was carried out by column chromatography (silica gel, 10-15% ethyl acetate/hexane). Methyl indoline-6-carboxylate (6 g; 75%) was obtained in the form of a solid.

Provenance & Evidence