反应详情

A suspension of methyl 5-bromo-2-hydroxy-3-nitrobenzoate (38.4 g, 0.14 mol), sodium acetate (19.63 g, 0.24 mol) and 10% Pd/C (3.84 g) in ethyl acetate (500 mL) and water (30 mL) was stirred at 25° C. under 1 atm of hydrogen for 16 hr. The mixture was filtered and the filtrate was washed with water (500 mL×2), brine (300 mL), dried over anhydrous sodium sulfate and concentrated to give crude product. The crude product was washed with methanol at 0° C. to give methyl 3-amino-2-hydroxybenzoate (13.67 g, yield 59%) as a light yellow solid. 1H-NMR (400 MHz, CDCl3-d) δ 3.88-3.94 (s, br, 2H), 3.91 (s, 3H), 6.70-6.74 (t, J=7.8 Hz, 1H), 6.88-6.90 (m, 1H), 7.24-7.26 (m, 1H), 10.91 (s, 1H); LC-MS (ESI) m/z 168 [M+1]−.

1. filtrationThe mixture was filtered
2. washthe filtrate was washed with water (500 mL×2), brine (300 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. concentrationconcentrated
5. customto give crude product
6. washThe crude product was washed with methanol at 0° C.