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, a solution of 75 g of 4-bromophenylacetic acid in 100 ml of THF is then added dropwise and the mixture is left stirring at −70° C. for 1 hour 30 minutes. 67.9 g of methyl 2,4-dichlorobenzoate are subsequently added dropwise, the mixture is left stirring for 30 minutes and then the temperature is allowed to rise to 5° C. The reaction mixture is poured onto an ice/1 liter of 2N HCl mixture and extracted with ether, the organic phase is washed with a saturated NaHCO3 solution and with water and dried over Na2SO4, the solvent is evaporated under vacuum to a volume of 200 ml, pentane is added and the crystalline product formed is filtered off. 80 g of the expected compound are obtained.

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