Hydrochloric Acid → 7,8-Difluoro-4h-benzo[1,4]oxazine-3-one-6-carboxylic acid

Participants

Reaction Steps

A 2M solution of aqueous sodium hydroxide (30 mL) was added to a suspension of 7,8-difluoro-6-methoxycarbonyl-4H-benzo[1,4]oxazine-3-one (4.8 g, 19.88 mmoL) in THF (100 mL). The mixture was allowed to stir for 3 hours and the total volume was then reduced in vacuo to half. It was treated with 2M hydrochloric acid to caused a solid precipitate which was filtered, washed with water three times and then dried in vacuo to give the title compound (3.6 g, 80%).

Provenance & Evidence