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

Participants

Reaction Steps

To a suspension of 2-amino-5-methoxy-benzoic acid (8.0 g, 47.8 mmol) in toluene (100 mL) was added a solution of phosgene (20%, 50.0 mL) in toluene and triethyl amine (13.40 mL). The reaction mixture was heated at 80 C. for 1.5 h. The precipitated product was filtered and washed with hexanes and toluene and dried to give 9.00 g of 6-methoxy-1H-benzo[d][1.3]oxazine-2,4-dione as a light brown solid. This was used directly for the next step.

Provenance & Evidence