反应详情

To a suspension of 3-chloro-4-hydroxy-5-methoxy-benzaldehyde (10 g, 54 mmol) in dichloromethane (300 mL) was added BBr3 (26.7 g, 107 mmol) dropwise at −40° C. under N2. After addition, the mixture was stirred at this temperature for 5 h and then was poured into ice water. The precipitated solid was filtered and washed with petroleum ether. The filtrate was evaporated under reduced pressure to afford 3-chloro-4,5-dihydroxybenzaldehyde (9.8 g, 89%), which was directly used in the next step.

1. additionAfter addition
2. filtrationThe precipitated solid was filtered
3. washwashed with petroleum ether
4. customThe filtrate was evaporated under reduced pressure