5-Methoxyindole → 5-methoxy-2,3-dihydro-1H-indole

Participants

Reaction Steps

At room temperature, to a solution of 5-(methyloxy)-1H-indole (12 g, 81.5 mmol, 1.0 eq) in acetic acid (150 mL) was added sodium cyanoborohydride (10.25 g, 163 mmol, 2.0 eq) in small portions, and the mixture was stirred overnight. The solvent was evaporated under reduced pressure and the residue was dissolved in ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogencarbonate solution and brine, and dried over Na2SO4. The solvent was removed under reduced pressure to give 5-(methyloxy)-2,3-dihydro-1H-indole (8.91 g, 45% yield) 1H NMR (CDCl3, 300 MHz) δ 6.76 (s, 1H), 6.60 (s, 2H), 3.54 (t, 2H), 3.01 (t, 2H).

Provenance & Evidence