反应详情

温度

-70 °C

436 ml of a 2M solution of the sodium salt of hexamethyldisilazane in THF are cooled to −60° C., under a nitrogen atmosphere, 400 ml of THF are added, followed by dropwise addition of a solution of 75 g of 4-bromophenylacetic acid in 100 ml of THF, and the mixture is stirred for 1 hour 30 minutes at −70° C. 67.9 g of methyl 2,4-dichlorobenzoate are then added dropwise and the mixture is stirred for 30 minutes and then allowed to warm to 5° C. The reaction mixture is poured into a mixture of ice/1 liter of 2N HCl and extracted with ether, the organic phase is washed with saturated NaHCO3 solution and with water, and dried over Na2SO4, the solvent is evaporated off under vacuum to a volume of 200 ml, pentane is added and the crystalline product formed is filtered off by suction. 80 g of the expected compound are obtained.

1. stirringthe mixture is stirred for 30 minutes
2. temperatureto warm to 5° C
3. extractionextracted with ether
4. washthe organic phase is washed with saturated NaHCO3 solution and with water
5. dry with materialdried over Na2SO4
6. customthe solvent is evaporated off under vacuum to a volume of 200 ml, pentane
7. additionis added
8. customthe crystalline product formed
9. filtrationis filtered off by suction