5-Fluoro-2-nitrobenzamide

394-02-5

77206-97-4

General procedure for the synthesis of 5-fluoro-2-nitrobenzamide from 5-fluoro-2-nitrobenzoyl chloride: anhydrous tetrahydrofuran (THF, 3 mL) solution of oxalyl chloride (1.83 g, 14.4 mmol) was added slowly and dropwise at 0 °C and under nitrogen protection to commercially available 5-fluoro-2-nitrobenzoic acid (1.78 g, 9.62 mmol) and N,N-dimethylformamide ( DMF, 40 mg) in a solution of anhydrous THF (10 mL). After the reaction mixture was stirred at room temperature for 1.5 h, the solvent was removed by vacuum evaporation to give 5-fluoro-2-nitrobenzoyl chloride (2.13 g) as a yellow oil. Subsequently, a solution of anhydrous THF (9 mL) of 5-fluoro-2-nitrobenzoyl chloride (1.53 g) was slowly added to pre-cooled 35% ammonia (30 mL) at room temperature. The reaction mixture was stirred for 45 min and extracted by adding dichloromethane (50 mL). The organic layer was separated and the aqueous layer was extracted once more with dichloromethane (50 mL). The combined organic phases were washed with saturated aqueous ammonium chloride solution (1 x 50 mL), dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated to dryness in vacuum to afford 5-fluoro-2-nitrobenzamide (1.04 g, 75% yield, liquid chromatographic purity >95%). Mass spectrometry analysis: [M+H]+=185.