O-Phenylenediamine → Benzimidazol-2-one

HRID 1390362Notes

Reaction equation

HRID 1390362 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].CN[C:11](NC)=[O:12]>ClC1C=CC=CC=1Cl>[N:7]1[C:11](=[O:12])[N:8]=[C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=12

Participants

4

Reactant 2

HCID 7243O-PhenylenediamineHCID 7293N,N'-Dimethylurea

Product 1

HCID 162542Benzimidazol-2-oneYield 93.6%

Reagents, catalysts & solvents 1

HCID 72391,2-DichlorobenzeneSolvent

Conditions

Temperature
172 °C

Procedure

216 Parts of o-phenylenediamine and 193.6 parts of N,N'-dimethyl urea are heated in 1000 parts of o-dichlorobenzene for 2 hours to 172° C. Methylanine evolves at 130° C. The suspension is stirred for a further 4 hours at 172° C, then cooled to room temperature and filtered by suction. The filter cake is washed with 800 parts by volume of ethanol and suspended in 1000 parts of water. This suspension is filtered by suction, washed with 100 parts of water and the filter cake is dried at 100° C, giving 250.8 parts (93.6% of theory) of benzimidazolone. The melting point of the product is between 312° and 315° C.

Workup

  1. customevolves at 130° C
  2. temperaturecooled to room temperature
  3. filtrationfiltered by suction
  4. washThe filter cake is washed with 800 parts by volume of ethanol
  5. filtrationThis suspension is filtered by suction
  6. washwashed with 100 parts of water
  7. customthe filter cake is dried at 100° C

Sources & evidence

ORD record
ord-e64b22ff6fa448f98944e6112bebd758
Source dataset
uspto-grants-1979_02
Patent number
US04138568

Reaction notes

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