Methanesulfonic Acid → 6-bromo-2-(3-methoxyphenyl)-1H-imidazo[4,5-b]pyridine

Participants

Reaction Conditions

Reaction Steps

Phosphorus pentaoxide (23.8 g) was added to methanesulfonic acid (85 ml), the mixture was stirred at 100° C. for 1 hour to give a solution. To the solution were added 2,3-diamino-5-bromopyridine (Compound of Reference Example 1) (15.8 g) and 3-methoxybenzoic acid (12.7 g), and the mixture was stirred at 100° C. for 1 hour. The reaction mixture was poured onto ice, neutralized with 8 N sodium hydroxide, and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried over MgSO4. The solvent was distilled off under reduced pressure, and crystals were collected by filtration to obtain 6-bromo-2-(3-methoxyphenyl)-1H-imidazo[4,5-b]pyridine (21.3 g, 84%).

Provenance & Evidence