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

HRID 2260341Notes

Reaction equation

HRID 2260341 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:5]2=[N:6][C:7](=[O:9])[N:8]=[C:4]2[CH:3]=1.C(O)C.[CH2:15]=[C:16]1[O:20][C:18](=[O:19])[CH2:17]1>O>[C:18]([NH:1][C:2]1[CH:11]=[CH:10][C:5]2=[N:6][C:7](=[O:9])[N:8]=[C:4]2[CH:3]=1)(=[O:19])[CH2:17][C:16]([CH3:15])=[O:20]

Participants

5

Reactant 3

HCID 702EthanolHCID 12661DiketeneHCID 152505475-amino-2H-1,3-benzodiazol-2-one

Product 1

HCID 117760583-Oxo-N-(2-oxo-2H-benzo[d]imidazol-5-yl)butanamide

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
85 °C

Procedure

An 82° C. solution of 2.86 kg (19.2 mol) of 5-amino-2-benzimidazolone and 24 kg of ethanol containing 50% by weight of water is metered per hour continuously and simultaneously with 2.06 kg (24 mol) of diketene (purity 98%) into a reactor equipped with a stirrer, reflux condenser, thermometer and, at the bottom, with a run-off. The light-colored suspension in the reactor is refluxed at about 85° C. with stirring and is kept to a constant volume of about 0.3 l by pumping out. The removed suspension is cooled down to about 15° C., and the light-colored crystals are separated by filtration from 22 kg per hour of mother liquor, washed with on average 6 kg per hour of 50% strength ethanol and dried, leaving 4.03 kg (17.3 mol) per hour of 5-acetoacetylamino-2-benzimidazolone as a virtually white crystalline powder. The yield based on amine is 90%.

Workup

  1. temperaturereflux condenser
  2. temperatureThe removed suspension is cooled down to about 15° C.
  3. customthe light-colored crystals are separated by filtration from 22 kg per hour of mother liquor
  4. washwashed with on average 6 kg per hour of 50% strength ethanol
  5. customdried

Sources & evidence

ORD record
ord-ffe3ac1c16b147688e8be5926a5a39c0
Source dataset
uspto-grants-1995_12
Patent number
US05476948

Reaction notes

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