反应详情

To a mixture of 2-amino-4,6-dimethoxybenzoic acid (7.888 g, 40 mmol) in MeOH (40 mL) and THF (40 mL) at room temperature was dropped 2.0 M solution of (trimethylsilyl)diazomethane in diethyl ether. The mixture was stirred at room temperature overnight. After the solvent was evaporated under reduced pressure, water and EtOAc was added to the residue. The organic layer was separated, dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by silica gel chromatography with 20-40% EtOAc/hexane as eluants to afford methyl 2-amino-4,6-dimethoxybenzoate as a solid (6.462 g, 76%). 1H NMR (300 MHz, CDCl3) δ 5.83 (d, 1H), 5.78 (d, 1H), 5.53 (br, 2H), 3.86 (s, 3H), 3.80 (s, 3H), 3.77 (s, 3H); LC-MS (ESI) m/z 212 (M+H)+.

1. customAfter the solvent was evaporated under reduced pressure, water and EtOAc
2. additionwas added to the residue
3. customThe organic layer was separated
4. dry with materialdried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. customThe crude product was purified by silica gel chromatography with 20-40% EtOAc/hexane as eluants