Diphosgene → 2-Chloro-4-fluoro-5-isocyanatophenyl methyl carbonate

Participants

Reaction Conditions

Reaction Steps

A solution of trichloromethyl chloroformate (19 ml, 158 mmol) in ethyl acetate (200 ml) was charged into a 500 ml-three neck flask equipped with a dropping funnel and a distillation apparatus and a solution of 2-fluoro-4-chloro-5-methoxycarbonyloxianiline (21.9 g, 100 mmol) in ethyl acetate (100 ml) was added dropwise in 20 minutes. After completion of addition, the mixture was heated at 80° C. and ethyl acetate was distilled off. After cooling, carbon tetrachloride (150 ml) was added and allowed the mixture to stand overnight. After removal of indissolved substances by filtration, the solvent was distilled off from filtrate under reduced pressure, whereby light brown solid of 2-fluoro-4-chloro-5-methoxycarbonyloxyphenyl isocyanate (20.6 g, yield 84%) was obtained.

Provenance & Evidence