3-Ethoxybenzoic acid → 6-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,3-diamino-5-bromopyridine (Compound of Reference Example 1) (1.13 g), 3-ethoxybenzoic acid (997 mg) and phosphorus oxychloride (24 ml) was stirred at 120° C. for 2 hours and poured onto ice. The mixture was neutralized with 8 N sodium hydroxide, stirred for 20 minutes and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water, dried over MgSO4. The solvent was distilled off under reduced pressure and the resulting crystals were collected by filtration to obtain 6-bromo-2-(3-ethoxyphenyl)-1H-imidazo[4,5-b]pyridine (978 mg, 51%).

Provenance & Evidence