反应详情

To a stirred mixture of 13.3 g of 3-bromo-2,5-difluorobenzaldehyde and 300 mL of THF cooled to -35°/-20° under an N2 atmosphere is added 30 mL of 2.85M of MeMgBr in Et2O over 10 minutes. The cooling bath is removed and the mixture stirred 1 hour and finally poured into 1 L of ice/H2O. 10% HCl is added to bring the pH to ~2 and the mixture extracted with 3×200 ml of CH2Cl2. The CH2Cl2 extracts are washed with H2O, saturated NaHCO3, H2O (250 mL each) and stripped to furnish 14.5 g of crude 3-bromo-2,5-difluoro-α-methylbenzyl alcohol. M+1 ions are observed at 236 and 238 in the mass spectrum. The crude material is used directly in the next step.

1. temperaturecooled to -35°/-20° under an N2 atmosphere
2. customThe cooling bath is removed
3. additionfinally poured into 1 L of ice/H2O
4. addition10% HCl is added
5. extractionthe mixture extracted with 3×200 ml of CH2Cl2
6. washThe CH2Cl2 extracts are washed with H2O, saturated NaHCO3, H2O (250 mL each)