69214-09-1

603301-13-9

69214-09-1

General procedure for the synthesis of 5-bromoimidazo[1,2-a]pyridines from 5-bromoimidazo[1,2-a]pyridine hydrobromide: 1. Preparation of reactants: 2-bromo-1,1-diethoxyethane (3.64 g, 18.48 mmol) was added to a solution of 6-bromopyridin-2-ylamine (1.0 g, 5.77 mmol) in n-butanol (40 mL). 2. Reaction conditions: the mixture was refluxed overnight and then cooled to room temperature. 3. post-processing: the reaction mixture was filtered to give 1.3 g (81% yield) of 5-bromoimidazo[1,2-a]pyridine hydrobromide as a white solid. esms (M + +1): 198.9 m/z. 4. Neutralization step: Saturated sodium bicarbonate solution (300 mL) was added to an ethyl acetate suspension of 5-bromoimidazo[1,2-a]pyridine hydrobromide (13.0 g, 46.96 mmol). 5. Isolation and purification: the organic layer was separated, washed with saturated sodium bicarbonate solution, dried with magnesium sulfate and concentrated under reduced pressure to give 9.7 g (100% yield) of 5-bromoimidazo[1,2-a]pyridine as a white solid.