反应详情

A suspension of methyl 5-fluoro-2-hydroxy-3-nitrobenzoate (2.3 g, 10.7 mmol), acetic acid (2 mL) and 10% Pd/C (0.23 g) in ethyl acetate (50 mL) was stirred at 25° C. over 1 atm hydrogen for 4 hr. The mixture was filtered and the filtrate was concentrated to give crude product. The crude product was purified by chromatography (silica gel, petroleum ether/ethyl acetate=100:1 to 20:1) to give methyl 3-amino-5-fluoro-2-hydroxybenzoate (2.0 g, yield 100%) as a light yellow solid. 1H-NMR (400 MHz, CDCl3-d) δ 3.95 (s, 3H), 3.98-4.13 (s, br, 2H), 6.60-6.63 (dd, J1=9.4 Hz, J2=2.4 Hz, 1H), 6.86-6.89 (dd, J1=8.8 Hz, J2=2.8 Hz, 1H), 10.70 (s, 1H); LC-MS (ESI) m/z 186 [M+1]+.

1. filtrationThe mixture was filtered
2. concentrationthe filtrate was concentrated
3. customto give crude product
4. customThe crude product was purified by chromatography (silica gel, petroleum ether/ethyl acetate=100:1 to 20:1)