Pyridine → 3-Chloroisatoic anhydride

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 2-amino-3-chlorobenzoic acid (0.86 g, 5.00 mmol) in anhydrous acetonitrile (10 mL), a solution of triphosgene (0.49 g, 1.65 mmol) in anhydrous CH2Cl2 (5 mL) and anhydrous pyridine (0.79 g, 10.0 mmol) were added, drop-wise at 55° C., simultaneously over a period of 10 minutes. After the addition was complete, the reaction mixture was stirred at 55° C. for another 2 hours. The solvents were removed under vacuum and water (50 mL) was added. The separated solid was filtered, washed with water, followed by chilled CH2Cl2 (10 mL) and dried under vacuum to give 8-chloro-1H-benzo[d][1,3]oxazine-2,4-dione as an off-white solid. Yield 0.82 g (83%).

Provenance & Evidence