反应详情

To the solution of 2-bromo-5-methoxy-benzaldehyde (10 g, 46.5 mmol) at −78° C. is added BBr3 (25 g, 93.75 mmol) and allowed to warm to room temperature. After 2 h, the reaction is quenched with water and extracted with ethyl acetate. The combined organic layers are washed with water, brine, dried over MgSO4, concentrated and purified by column chromatography to afford 3.6 g of 2-bromo-5-hydroxy-benzaldehyde. To the solution of 2-bromo-5-hydroxy-benzaldehyde (1.45 g, 7.2 mmol in benzene (30 ml) and THF (6 ml) is added 1,3-propanediol (2.74 g, 36 mmol) and TsOH (37 mg, 0.22 mmol). The mixture is refluxed for 24. After cooling down, the solvent is evaporated. The residue is loaded on silica and purified by column chromatography to afford the titled compound (2.3 g) as brown oil.

1. temperatureThe mixture is refluxed for 24
2. temperatureAfter cooling down
3. customthe solvent is evaporated
4. custompurified by column chromatography