Synthesis
General procedure for the synthesis of 3-bromo-2-(bromomethyl)pyridine from 2-methyl-3-bromopyridine: a mixture of 2-methyl-3-bromopyridine (1 g, 5.8 mmol), benzoyl peroxide (101 mg, 0.4 mmol) and N-bromosuccinimide (NBS, 1.1 g, 6.39 mmol) in carbon tetrachloride (CCI4, 58 mL) was was heated under reflux conditions for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature, the reaction was quenched with water (H2O) and extracted with dichloromethane (DCM, 3 x 30 mL). The organic layers were combined, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (CC), and 3-bromo-2-(bromomethyl)pyridine (1.1 g, 78% yield) was obtained as a yellow oil using a solvent mixture of petroleum ether (PE) and ethyl acetate (EA) (15:1) as eluent.
References
[1] Patent: WO2011/107248, 2011, A1. Location in patent: Page/Page column 43
[2] Patent: EP2784077, 2014, A1. Location in patent: Paragraph 0060; 0061
[3] Patent: US2014/343089, 2014, A1. Location in patent: Paragraph 0066
[4] Patent: WO2009/51715, 2009, A1. Location in patent: Page/Page column 33
[5] Patent: WO2004/98607, 2004, A1. Location in patent: Page/Page column 51
