Ammonium Hydroxide → Isoquinolin-6-ol

Participants

Reaction Steps

Heat a mixture of 6-methoxy-isoquinoline (2.1 g, 13.2 mmol) and pyridine hydrochloride (30 g) in a heavy walled screw cap sealed tube at 160° C. overnight. Cool to room temperature, add water and concentrated ammonium hydroxide to bring the pH of the mixture to 10-11, extract with ethyl acetate (4 times), wash the combined organic extracts with water (4 times), and concentrate under reduced pressure. Purification by medium pressure liquid chromatography eluting with 0-3% of 2N NH3/MeOH in dichloromethane afford the title compound (520 mg, 27%): δH (DMSO-d6, 400 MHz): 7.09 (s, 1H), 7.19 (dd, 1H, J=9, 2 Hz), 7.56 (d, 1H, J=6 Hz), 7.94 (d, 1H, J=9 Hz), 8.29 (d, 1H, J=6 Hz), 9.05 (s, 1H), 10.36 (s, 1H).

Provenance & Evidence