Diphenylmethane → 6-methoxyisoquinolin-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

Ethyl chloroformate (4.3 mL, 44.5 mmol) was added drop wise at 0° C. to a solution of 3-methoxycinnamic acid (5.3 g, 29.7 mmol) and triethylamine (8.3 mL, 59.4 mmol) in acetone (35 mL). After 1 hour at 0° C., aqueous sodium azide (3.1 g, 47.5 mmol, 16 mL water) was added drop wise, and the reaction mixture was stirred at 23° C. for 16 hours. Water (50 mL) was added to the mixture and the volatile removed under reduced pressure. The resulting slurry was extracted with toluene (3×25 mL) and the combined organic layers were dried over magnesium sulfate. The dried solution was filtered and added dropwise to a solution of diphenylmethane (25 mL) and tributylamine (14.2 mL, 59.4 mmol) at 190° C. The toluene was distilled off as added. After complete addition, the reaction temperature was raised to 210° C. for 2 hours. After cooling, the precipitated product was collected by filtration, washed with hexanes, and dried under vacuum to yield 6-methoxyisoquinolin-1(2H)-one (1.7 g, 9.7 mmol, 33% yield). MS m/z 176 (M++H).

Provenance & Evidence