Triphosgene → 6-hydroxy-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Participants

Reaction Steps

5-Hydroxyanthranilic acid (9.5 g, 62 mmol) was suspended in dioxane (50 mL), bis(trichloromethyl)carbonate (6 g, 20 mmol) was added (slightly exothermic), the suspension was refluxed for 1 h, allowed to cool to rt, the solid was filtered off and washed with dioxane, affording brown crystals (10.1 g, 90%), mp. 236° C. (dec).

Provenance & Evidence