Acetic Anhydride → 8-methylisoquinolin-1(2H)-one

Participants

Reaction Steps

A solution of 8-methylisoquinoline 2-oxide (1.4 g, 8.8 mmol) in Ac2O (20 mL) was refluxed for 3 hours. The mixture was concentrated under vacuum and the residue was dissolved in MeOH (20 mL). To the reaction mixture was added aq. NaOH (20 mL, 1M). The mixture was refluxed for 1 hour and stirred at room temperature for 10 hours. The mixture was concentrated under vacuum. The residue was diluted with water (20 mL) and extracted with EtOAc (3×20 mL). The combined organic layers were washed with brine (2×10 mL), dried over Na2SO4, filtered, and concentrated under vacuum. The residue was purified by column chromatography (petroleum ether/EtOAc, 3:1) to give 8-methylisoquinolin-1(2H)-one (76a, 1 g, 71%) as a yellow solid.

Provenance & Evidence