Diphosgene → 8-methyl-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione

Participants

Reaction Steps

To a solution of 2-amino-3-methylbenzoic acid (6 g) in dry 1,4-dioxane (50 mL) was added dropwise a solution of trichloromethyl chloroformate (8 mL) in dry 1,4-dioxane (25 mL), with ice-water cooling to keep the reaction temperature below 25° C. A white precipitate began to form during the addition. The reaction mixture was stirred at room temperature overnight. The precipitated solids were removed by filtration and washed with 1,4-dioxane (2×20 mL) and hexane (2×15 mL) and air-dried to yield 6.51 g of off-white solid.

Provenance & Evidence