Methanesulfonic Acid → HCID 67383001, compound

Participants

Reaction Steps

A flask charged with 2-(4-bromo-3-fluorophenoxy)-5-iodonicotinic acid (109 g, 249 mmol) and phosphorus pentoxide (70.6 g, 497 mmol) was treated with methanesulfonic acid (484 mL, 7460 mmol). After stirring for 30 minutes at room temperature, the reaction mixture was heated to 120° C. for 18 h. The reaction mixture was allowed to cool to room temperature and was poured into 1 L of ice water. After stirring for one hour, the resulting solid was filtered and subsequently washed sequentially with water and MeOH. The solid was dried to provide a 1:4 mixture of 7-bromo-6-fluoro-3-iodo-5H-chromeno[2,3-b]pyridin-5-one and 7-bromo-8-fluoro-3-iodo-5H-chromeno[2,3-b]pyridin-5-one (81.92 g, 195 mmol, 78% yield) as an off white solid.

Provenance & Evidence