Pyridine → 6-methoxy-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-amino-5-methoxy-benzoic acid (1.50 g, 8.97 mmol) in anhydrous acetonitrile (15 mL) at 50-55° C. were simultaneously added pyridine (1.42 g, 17.9 mmol) and a solution of triphosgene (0.870 g, 2.96 mmol) in anhydrous dichloromethane (20 mL) over 20 min span, and the reaction was stirred at 50-55° C. for 2 hours. The solvent was removed and the residue was mixed with water (100 mL), the solid was filtered and rinsed with cold water (30 mL) and dried. The crude was further washed with ether (20 mL) to give 6-methoxy-1H-benzo[d][1,3]oxazine-2,4-dione. Yield: 1.55 g (89%).

Provenance & Evidence