Ammonium Hydroxide → 8-fluoro-5-nitroisoquinoline

Participants

Reaction Conditions

Reaction Steps

To a solution of 8-fluoroisoquinoline (Description 41; 1.24 g, 8.4 mmol) in concentrated sulfuric acid (10 ml) cooled to between −5° C. and 0° C. was added slowly, over 10 minutes, a solution of potassium nitrate (0.93 g, 9.24 mmol) in concentrated sulfuric acid (5 ml). The mixture was stirred at 0° C. for 30 minutes after which time TLC indicated that reaction was complete. The mixture was poured onto ice (100 g) and basified by the careful addition of 33% aqueous ammonium hydroxide. The mixture was extracted with dichloromethane (3×150 ml) and the combined organic layers were washed with brine, dried over Na2SO4 and filtered through a 1 inch plug of silica gel. The silica gel plug was further washed with 150 ml of a 1:1 mix of ethyl acetate and iso-hexanes. The combined organics were evaporated to give the title compound (1.33 g, 82%) as a brown solid.

Provenance & Evidence