Carbon tetrabromide → 1-Bromo-4-(bromomethyl)-2-methylbenzene

HRID 419955Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8]O)=[CH:4][C:3]=1[CH3:10].C(Br)(Br)(Br)[Br:12].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>C(Cl)Cl>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][Br:12])=[CH:4][C:3]=1[CH3:10]

Participants

Conditions

Temperature: 0 °C

Procedure

(4-Bromo-3-methylphenyl)methanol (14.4 g, 71.6 mmol) is dissolved in anhydrous CH2Cl2 (150 mL) and CBr4 (26.1 g, 79.0 mmol) is added. The reaction mixture is cooled to 0° C. and PPh3 (20.7 g, 79.0 mmol) is added in small portions. The reaction mixture is stirred 2 h and the triphenylphosphine oxide that forms is filtered off and the solvent removed in vacuo. The resulting semi solid is filtered on a silica gel pad and rinsed with hexane/EtOAc (9:1) to provide the expected product 1-Bromo-4-(bromomethyl)-2-methylbenzene as a clear oil contaminated with bromoform which is used directly in the next step. 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 4.39-4.44 (m, 3H) 7.07 (dd, J=8.20, 2.34 Hz, 1H) 7.26 (t, J=1.17 Hz, 1H) 7.49 (d, J=8.20 Hz, 1H)

Workup

filtrationthe triphenylphosphine oxide that forms is filtered off
customthe solvent removed in vacuo
filtrationThe resulting semi solid is filtered on a silica gel pad
washrinsed with hexane/EtOAc (9:1)

Sources & evidence

ORD record: ord-0a5095a40b8941d593591abe03e3e3b2
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08093402B2

Reaction notes

Loading…