Nitric Acid → 1-(4-Fluoro-5-nitroindolin-1-yl)ethan-1-one

Participants

Reaction Conditions

Reaction Steps

Fuming nitric acid (0.22 mL) was added dropwise to a solution of 1-(4-fluoro-indolin-1-yl)ethanone (1 g, 5.58 mmol) in concentrated sulfuric acid (10 mL) at −15° C. to 0° C. The reaction mixture was stirred at 0° C. for 2 h and then the resulting mixture was basified with sodium bicarbonate solution (100 mL). The reaction mixture was partitioned between chloroform (100 mL) and water (100 mL). The organic layer was separated and the aqueous layer was extracted with chloroform (5×30 mL). The combined organic layers were washed with water (3×20 mL), brine (3×20 mL), dried over anhydrous sodium sulphate and concentrated in vacuo to give the crude product. Purification by column chromatography over neutral alumina using 10-12% ethyl acetate in hexane as eluent afforded 1-(4-fluoro-5-nitro-indolin-1-yl)ethanone (0.56 g, 45%) as a yellow solid.

Provenance & Evidence