Synthesis
In a 6-liter reactor equipped with a condenser, a central mechanical stirrer, and a thermometer, introduce 575 g (2.5 mol) of methyl 4-bromo-3-methylbenzoate, 3 liters of methylene chloride, 494 g (2.75 mol) of N-bromosuccinimide and 17 g of benzoyl peroxide (0.05 mol; 70percent in water). Heat the mixture at reflux under irradiation with a 1000-watt lamp for 10 h. Wash the mixture twice with 1 liter of water, then with 1 liter of saturated sodium chloride solution. Evaporate the methylene chloride. Recrystallize the crude product obtained from heptane. This gives 596 g of 4-bromo-3-bromomethyl-benzoic acid methyl ester as off-white crystals.
References
[1] Patent: US2007/15931, 2007, A1. Location in patent: Page/Page column 6
[2] Patent: US2010/4159, 2010, A1. Location in patent: Page/Page column 59; 62
[3] Patent: WO2006/110173, 2006, A2. Location in patent: Page/Page column 78-79
[4] Chemische Berichte, 1993, vol. 126, # 7, p. 1635 - 1642
[5] ChemMedChem, 2015, vol. 10, # 4, p. 688 - 714
