反应详情

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

1. additionis added
2. customto rise to 5° C
3. extractionextracted with ether
4. washthe organic phase is washed with a saturated NaHCO3 solution
5. dry with materialwith water, dried over Na2SO4
6. customthe solvent is evaporated under vacuum to a volume of 200 ml, pentane
7. additionis added
8. customthe crystalline product that forms is dried