反应详情

温度

-78 °C

At −78° C., 34.7 ml (69.4 mmol) of a 2 M lithium diisopropylamide solution are slowly added dropwise to a solution of 10.0 g (69.34 mmol) of tert-butyl 2-methylpropionate (Example I-1) in 100 ml of tetrahydrofuran. After the addition has ended, the mixture is stirred at −78° C. for 1 h, and a solution of 15.76 g (63.04 mmol) of 4-bromobenzyl bromide in 10 ml of tetrahydrofuran is then added and the mixture is stirred at −78° C. for 1 h. The reaction is then warmed to room temperature and poured into 100 ml of 1 N hydrochloric acid, the phases are separated and the aqueous phase is extracted 3× with diethyl ether. The combined organic phases are washed with NaHCO3 solution, dried over sodium sulphate and freed from the solvent under reduced pressure. Distillative purification of the residue under oil pump vacuum gives 16.75 g (85%) of tert-butyl 3-(4-bromophenyl)-2,2-dimethylpropionate.

1. customAt −78° C.
2. additionAfter the addition
3. stirringthe mixture is stirred at −78° C. for 1 h
4. temperatureThe reaction is then warmed to room temperature
5. customthe phases are separated
6. extractionthe aqueous phase is extracted 3× with diethyl ether
7. washThe combined organic phases are washed with NaHCO3 solution
8. dry with materialdried over sodium sulphate
9. distillationDistillative purification of the residue under oil pump vacuum