反应详情

温度

-5 °C

Thionyl chloride (2.38 g, 20 mmol) was added slowly to a solution of 2-fluoro-4-nitrobenzoic acid (2.97 g, 16 mmol) in DMF (50 ml) cooled at −5° C. The mixture was stirred for an additional 1 hour at −5° C. Methylamine (0.62 g, 20 mmol; freshly distilled from its 40% aqueous solution) was added to the reaction medium. The second mixture was stirred for an additional 1 hour. Ethyl acetate (300 ml) was added to the mixture, which was washed with brine (3×150 ml). The organic layer was dried over MgSO4, and concentrated to yield N-methyl-2-fluoro-4-nitrobenzamide (52a) (2.89 g, 14.6 mmol, 91%) as a yellow solid. 1H NMR (Acetone d6, 400 MHz) δ 3.05 (d, J=4.3 Hz, 3H), 6.31 (dd, J=13.5, 2.1 Hz, 1H), 6.40 (dd, J=8.5, 2.1 Hz, 1H), 7.64 (dd, J=8.6, 8.6 Hz, 1H).

1. distillationfreshly distilled from its 40% aqueous solution)
2. additionwas added to the reaction medium
3. stirringThe second mixture was stirred for an additional 1 hour
4. additionEthyl acetate (300 ml) was added to the mixture, which
5. washwas washed with brine (3×150 ml)
6. dry with materialThe organic layer was dried over MgSO4
7. concentrationconcentrated