Yield:-

Reaction Conditions:

with bromine in acetic acid at 20; for 1 h;

Steps:

G2
To 6-chloro-imidazo[1,2-a]pyridine (1 eq, 253 mmol, 39 g) in acetic acid (500 ml) under inert atmosphere, is added dropwise bromine (1 eq, 253 mmol, 13 ml). After 1 hour stirring at room temperature, the reaction mixture is filtered and to give a beige solid (64 g) 3-Bromo-6-chloro-imidazo[1,2-a]pyridine hydrobromide;[M+H]⁺ 232(234)

References:

NOVARTIS AG WO2009/50183, 2009, A2 Location in patent:Page/Page column 118