反应详情

A mixture of N-methyl-2-fluoro-4-nitrobenzamide (52a) (2.89 g, 14.6 mmol) and iron (5.04 g, 90 mmol) in ethyl acetate (40 ml) and acetic acid (40 ml) was refluxed for 1 hour. The solid particles were filtered off. The filtrate was washed with water and extracted with ethyl acetate. The organic layer was dried over MgSO4, concentrated and chromatographed (dichloromethane:acetone, 95:5) to yield N-methyl-2-fluoro-4-aminobenzamide (52b) (2.3 g, 13.7 mmol, 94%) as an off-white solid. 1H NMR (acetone-d6, 400 MHz) δ 2.86 (d, J=4.3 Hz, 3H), 5.50 (bs, 2H), 6.37 (dd, J1=14.7 Hz, J2=2.1 Hz, 1H), 6.50 (dd, J=8.5, 2.1 Hz, 1H), 7.06 (bs, 1H), 7.68 (dd, J=8.8 8.8 Hz, 1H); 13C NMR (acetone-d6, 100 MHz) δ 25.8, 99.6 (d, J=13.8 Hz), 109.2 (d, J=12.8 Hz), 110.0 (d, J=1.6 Hz), 132.5 (d, J=4.8 Hz), 153.5 (d, J=12.6 Hz), 162.2 (d, J=242.5 Hz), 164.0 (d, J=3.1 Hz).

1. temperaturewas refluxed for 1 hour
2. filtrationThe solid particles were filtered off
3. washThe filtrate was washed with water
4. extractionextracted with ethyl acetate
5. dry with materialThe organic layer was dried over MgSO4
6. concentrationconcentrated
7. customchromatographed (dichloromethane:acetone, 95:5)