Diphosgene → 5-Methylisatoic anhydride

Participants

Reaction Steps

Trichloromethyl chloroformate (36.27 mL, 300 mmol) was added to a stirred solution of Compound 10 (41.3 g, 273 mmol) in dry dioxane at room temperature and the solution was refluxed for 4 h. The solution was cooled in ice bath and the solids formed were filtered. The solids were washed by ether and dried under vacuum at room temperature to yield 45.5 g (94%) of white solids. M.P. 257° C. 1H NMR (DMSO-d6): δ 2.32 (s, 3H), 7.06 (d, J=8.6 Hz, 1H), 7.56 (dd, J=8.6, 1.8 Hz, 1H), 7.71 (d, J=1.1, 1H), 11.63 (s, 1H). EIMS (neg. mode) m/z 176 (M−1), 152 (M+23). Anal. (C9H7NO3) C, H, N.

Provenance & Evidence