Yield:246139-76-4 89%

Reaction Conditions:

with bromine;dibenzoyl peroxide in tetrachloromethane;Reflux;

Steps:

20b 2-Bromo-1-(bromomethyl)-4-tert-butylbenzene

20b)
2-Bromo-1-(bromomethyl)-4-tert-butylbenzene
To a mixture of 227 g (1.00 mol) of 2-bromo-4-tert-butyl-1-methylbenzene, 160 g (1.00 mol) of bromine and 1.4 liter of CCl₄ 1.0 g of benzoyl peroxide was added.
This mixture was refluxed until evolution of hydrogen bomide was stopped, and red color of bromine disappeared.
The resulting mixture was evaporated using rotary evaporated.
Fractional rectification of the residue gave 273 g (89%) of the title product, b.p. 138-141°C/4 mm Hg. Anal. calc. for C₁₁H₁₄Br₂: C, 43.17; H, 4.61. Found: C, 43.30; H, 6.72. ¹H NMR (CDCl₃): δ 7.56 (d, J = 1.8 Hz, 3-H), 7.37 (d, J = 8.1 Hz, 1H, 5-H), 7.30 (dd, J = 8.1 Hz, J = 1.8 Hz, 1H, 6-H), 4.59 (s, 2H, CH₂Br), 1.29 (s, 9H, ^tBu).
¹³C{¹H} NMR (CDCl₃): δ 153.9, 133.9, 130.9, 130.4, 125.1, 124.4, 34.7, 33.4, 31.06.

References:

EP2368896,2011,A1 Location in patent:Paragraph 0242