Potassium Hydroxide → HCID 67240458, compound

Participants

Reaction Steps

A slurry of 5-bromo-2-(4-methoxyphenoxy)nicotinic acid (12.2 g, 37.6 mmol) and polyphosphoric acid (200 g) was heated at 135° C. for 1.5 h. The reaction was cooled to rt and poured onto 300 g of ice before being basified to pH 12 with 50% aq. KOH (1.5 L). The resulting yellow slurry was filtered and washed with 100 mL of ether. The wet solid was then partitioned between water and DCM (1:1, 2000 mL). The layers were separated and the aqueous layer was extracted with DCM 5×500 mL. The combined organics were washed with brine, dried over sodium sulfate, filtered and concentrated to provide 3-bromo-7-methoxy-5H-chromeno[2,3-b]pyridin-5-one as a yellow solid.

Provenance & Evidence