反应详情

A mixture comprising 2,4-difluoro-5-nitrobenzonitrile (9.03 g, 0.049 mol) and ethanol (10-15 mL) was stirred at ambient temperature while concentrated ammonium hydroxide (40 mL) was slowly added to give a precipitate. The precipitate was isolated by filtration and lyophilized to give 4-amino-2-fluoro-5-nitrobenzonitrile (7.84 g, 0.043 mol) as an off-white solid; PB-CI/MS: 182=(MH+); 1H-NMR (300 Mhz, DMSO-d6): 6.856(d, 1H), 8.22(bs, 2H), 8.577(d, 1H). A mixture of 4-amino-2-fluoro-5-nitrobenzonitrile (3 g, 0.017 mol), PtO2 (≈300 mg) and methanol (20 mL)was hydrogenated (1 atm) for approximately 12 hours, filtered over celite and concentrated to dryness to provide 4,5-diamino-2-fluorobenzonitrile (2.5 g, 0.017 mol) as a brown solid PB-CI/MS: 152=(MH+); 1H-NMR (300 Mhz, DMSO-d6): 4.7(bs, 2H), 5.863(bs, 2H), 6.375(d, 1H), 6.56(d, 1H).

1. customfor approximately 12 hours
2. filtrationfiltered over celite and
3. concentrationconcentrated to dryness