18112-31-7

The general procedure for the synthesis of 6-chloro-2-methyl-3-bromo-imidazo[1,2-b]pyrazines using 6-chloro-2-methylimidazo[1,2-b]pyridazine as starting material was as follows: 6-chloro-2-methylimidazo[1,2-b]pyridazine (2.00 g, 11.9 mmol, 1.0 eq.) was dissolved in chloroform (50 mL), followed by N-bromosuccinimide (2.55 g, 14.3 mmol, 1.2 eq.). The reaction mixture was stirred at room temperature for 15 hours. Upon completion of the reaction, the product was purified by column chromatography using a hexane solution of 50% ethyl acetate as eluent, resulting in 2.64 g of yellow solid product in 90% yield.

[1] Patent: US2014/256733, 2014, A1. Location in patent: Paragraph 0266; 0269-0270
[2] Patent: WO2008/52733, 2008, A1. Location in patent: Page/Page column 81