Synthesis
General procedure for the synthesis of 5-bromo-1,2-dimethylimidazole from 1,2-dimethylimidazole: N-bromosuccinimide (NBS) (169 mg, 0.95 mmol) was added to a solution of dimethylformamide (DMF) (5 mL) of 1,2-dimethyl-1H-imidazole (1a) (96 mg, 1 mmol) at room temperature, and the reaction mixture was to be stirred for 3 hours away from light. After completion of the reaction, the resulting orange-yellow solution was diluted with ethyl acetate (EtOAc) (50 mL) and washed sequentially with 10% aqueous sodium hydroxide (2 x 50 mL), water (50 mL) and saturated saline (50 mL). The aqueous phase was then back-extracted with ethyl acetate (50 mL), and all organic phases were combined, dried with anhydrous sodium sulfate (Na2SO4) and filtered. The filtrate was concentrated under reduced pressure to give 5-bromo-1,2-dimethylimidazole as colorless crystals (3.78 g, 76% yield).
References
[1] Advanced Synthesis and Catalysis, 2016, vol. 358, # 4, p. 597 - 609
[2] Tetrahedron, 2004, vol. 60, # 37, p. 8065 - 8071
[3] Patent: US2014/107097, 2014, A1. Location in patent: Paragraph 0332
[4] Tetrahedron Letters, 2015, vol. 56, # 25, p. 3855 - 3857
