Phosgene → Benzimidazol-2-one

Participants

Reaction Steps

100 g (1.01 mol) of phosgene are passed into 108 g (1 mol) of o-phenylenediamine in 800 ml of water at 80° C. over a period of 4 hours and the pH is kept constant at 6.5 by simultaneous metering in of 231 g (1.9 mol) of 50% strength aqueous sodium hydroxide solution. After filtration with suction and washing with water, 126 g of benzimidazol-2-one are obtained, which corresponds to a yield of 94% of theory.

Provenance & Evidence