反应详情

2.0 g of methyl 2-ethyl-4-methoxy-3-methylbenzoate are dissolved in 50 ml of DCM in a 100 ml round-bottomed flask, and BBr3 is carefully added dropwise at 0° C. The mixture is left to stir at RT for 4 hours. The solvent is distilled off in vacuo, methanol is carefully added to the residue at 0° C., and the mixture is evaporated again in a rotary evaporator. This operation is repeated a further twice, giving 1.88 g of methyl 2-ethyl-4-hydroxy-3-methylbenzoate as oil, which is employed for the next step without further purification; MS-FAB (M+H+)=195,2; Rf (polar method): 1.96 min.

1. waitThe mixture is left
2. distillationThe solvent is distilled off in vacuo, methanol
3. additionis carefully added to the residue at 0° C.
4. customthe mixture is evaporated again in a rotary evaporator