2-(2-Fluoro-4-iodophenylamino)-6-formylaminomethylnicotinic acid methyl ester → 5-(2-Fluoro-4-iodophenylamino)imidazo[1,5-a]pyridine-6-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of 2-(2-fluoro-4-iodophenylamino)-6-formylaminomethylnicotinic acid methyl ester (11.6 g, 27.4 mmol) in toluene (160 mL) was added phosphorous (V) oxychloride (5.1 mL, 54.8 mmol) and the reaction mixture heated at 95° C. for 1 hour. The reaction mixture was concentrated in vacuo and the resultant residue poured onto ice. The mixture was washed with aqueous saturated sodium hydrogen carbonate solution (40 mL) and the aqueous layer extracted twice with ethyl acetate (2×30 mL). The combined organic extracts were washed with brine (30 mL), dried (MgSO4), filtered and concentrated in vacuo. The resultant residue was subjected to flash chromatography (SiO2, gradient 0-70% ethyl acetate in DCM) to yield the title compound as a brown oil (5.6 g, 50%). LCMS (Method B): RT=3.62 min, M+H+=412.

Provenance & Evidence