Hydrogen Bromide → Methyl 2-(2,6-Dipropyl-4-Bromomethyl-Phenoxy)Phenylacetate

Reaction equation

[CH2:1]([C:4]1[CH:21]=[C:20]([CH2:22]O)[CH:19]=[C:18]([CH2:24][CH2:25][CH3:26])[C:5]=1[O:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[CH2:13][C:14]([O:16][CH3:17])=[O:15])[CH2:2][CH3:3].P(Br)(Br)[Br:28].Br>C(Cl)(Cl)(Cl)Cl>[CH2:1]([C:4]1[CH:21]=[C:20]([CH2:22][Br:28])[CH:19]=[C:18]([CH2:24][CH2:25][CH3:26])[C:5]=1[O:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[CH2:13][C:14]([O:16][CH3:17])=[O:15])[CH2:2][CH3:3]

Participants

Procedure

To a solution of 2.66.1 g (7.46 mmol) of the product of Step A dissolved in 15 mL of carbon tetrachloride was added 0.709 mL (7.47 mmol) of phosphorous tribromide and the reaction mixture was magnetically stirred at room temperature for 30 min as hydrogen bromide was evolved. The magnetic stir bar was removed, and the reaction mixture was concentrated in vacuo. The residue was redissolved and evaporated from carbon tetrachloride several times to remove most of the hydrogen bromide. Finally, the residue was purified by rapid flash chromatography on a silica gel column eluted with 10% EtOAc-hexane. Combination and evaporation of the purified fractions and drying in vacuo afforded 2.129 (68%) of the title compound which was used directly in the next step without further characterization.