Ethanol → 3-Oxo-N-(2-oxo-2H-benzo[d]imidazol-5-yl)butanamide

Participants

Reaction Steps

The mother liquor obtained is re-used in four further reaction cycles by using it at 80° C. to replace fresh ethanol containing 50% by weight of water for dissolving 2.86 kg per hour of 5-amino-2-benzimidazolone at such a rate that 26.86 kg per hour of amine solution can be reacted as described above with 2.06 kg per hour of diketene. Workup gives 4.25 to 4.34 kg per hour of 5-acetoacetylamino-2-benzimidazolone of consistent quality, corresponding to a yield of 95 to 97% based on amine.

Provenance & Evidence