反应详情

5-(3-Amino-2-methoxy-phenyl)-furan-2-carboxylic acid methyl ester 54b (350 mg, 1.42 mmol) was dissolved in dichloromethane followed by dropwise addition of boron tribromide (3.3 mL, 2.0 mol/L). The reaction mixture was stirred at room temperature for 2 hours. The reaction was monitored by TLC until the disappearance of the starting materials and quenched with methanol. The mixture was adjusted to pH 5˜6 with saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The organic layers were concentrated and then the resulting residue was purified by silica gel column chromatography to obtain the title compound 5-(3-amino-2-hydroxy-phenyl)-furan-2-carboxylic acid methyl ester 54c (170 mg, yield 45.1%) as a grey solid.

1. customquenched with methanol
2. extractionextracted with ethyl acetate
3. concentrationThe organic layers were concentrated
4. customthe resulting residue was purified by silica gel column chromatography