Phosgene → 6-Methoxy-7-nitro-2H-3,1-benzoxazine-2,4(1H)-dione

Participants

Reaction Conditions

Reaction Steps

2.0 g (9.4 mmol) of 2-amino-5-methoxy-4-nitrobenzoic acid were dissolved in 20 ml of chloroform and 10 ml of tetrahydrofuran, and 20 ml of 20% strength phosgene solution (1.8 M in toluene) were added. After 3 hours under reflux, a further 10 ml of phosgene solution were added at 60° C., and the mixture was stirred at 60° C. for a further 12 hours. The phosgene was distilled off and the residue was concentrated in vacuo after addition of toluene several times. 2.2 g (100%) of the desired product were obtained.

Provenance & Evidence