Phosgene → 5-Fluoroisatoic anhydride

Participants

Reaction Conditions

Reaction Steps

2-Amino-5-fluorobenzoic acid (1.91 g, 12.3 mmol) was dissolved in 1N sodium hydroxide solution (15 mL) and cooled to 0° C. under a nitrogen atmosphere. Phosgene (10 mL of a 20% solution in toluene) was added dropwise. After the addition was complete, the thick slurry was allowed to warm to room temperature. The precipitate was filtered off and rinsed with deionized water (2×50 mL). The precipitate was slurried in diethyl ether (50 mL), filtered, and dried under reduced pressure to yield 2.04 g of 6-fluoro-2H-3,1-benzoxazine-2,4(1H)-dione.

Provenance & Evidence