Hydrochloric Acid → Tert-butyl 3-(4-bromophenyl)-2,2-dimethylpropionate

HRID 353164Notes

Reaction equation

C([N-]C(C)C)(C)C.[Li+].[CH3:9][CH:10]([CH3:18])[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12].[Br:19][C:20]1[CH:27]=[CH:26][C:23]([CH2:24]Br)=[CH:22][CH:21]=1.Cl>O1CCCC1>[Br:19][C:20]1[CH:27]=[CH:26][C:23]([CH2:24][C:10]([CH3:18])([CH3:9])[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])=[CH:22][CH:21]=1

Participants

Conditions

Temperature: -78 °C

Procedure

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.

Workup

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

Sources & evidence

ORD record: ord-30e3520047f44b26a367f3c2089eedd4
Source dataset: uspto-grants-2004_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06750236B2

Reaction notes

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