6-(Benzyloxy)-5-methoxy-1H-indole

75-52-5

2426-84-8

2426-59-7

To a solution of 4-(benzyloxy)-5-methoxy-2-nitrobenzaldehyde (8.60 g, 30 mmol) in acetic acid (80 mL) was added nitromethane (10 mL) and ammonium acetate (3.66 g, 60 mmol, 2 eq.) sequentially. The reaction mixture was stirred at 100 °C for 5 hours. Upon completion of the reaction, the reaction solution was concentrated under reduced pressure and the resulting residue was dissolved in a solvent mixture of toluene (80 mL) and acetic acid (10 mL). To this solution was added iron powder (3.3 g, 60 mmol, 2 eq.) and silica gel (10 g), and the reaction mixture was heated to reflux for 1 hour. The reaction solution was cooled to room temperature and filtered and the filtrate was concentrated under reduced pressure. The concentrated residue was partitioned between water and ethyl acetate, the organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated. Finally, the residue was purified by silica gel column chromatography (petroleum ether/ethyl acetate = 3/1) to afford the target product 6-(benzyloxy)-5-methoxy-1H-indole (3.0 g, 11.8 mmol, 39.3% yield) as a yellow solid.