Urea → 1-methyl-2,3-dihydro-1H-1,3-benzodiazol-2-one

HRID 461228Notes

Reaction equation

HRID 461228 reaction equation
[CH3:1][NH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[NH2:9].N[C:11](N)=[O:12]>>[CH3:1][N:2]1[C:3]2[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=2[NH:9][C:11]1=[O:12]

Participants

3

Reactant 2

HCID 1176UreaHCID 78498N-Methyl-o-phenylenediamine

Product 1

HCID 5905401-methyl-2,3-dihydro-1H-1,3-benzodiazol-2-oneYield 26.5%

Conditions

Temperature
175 °C

Procedure

A mixture of 24.4 grams (0.2 mole) of N-methyl-o-phenylenediamine and 14.4 grams (0.24 mole) of urea was prepared. The mixture was stirred for 16 hours in an oil bath maintained at 175° C. The reaction mixture then was cooled to about 80° C., 250 ml. of alcohol were added, and the mixture was refluxed for 20 minutes and then was filtered while hot. The filtrate was allowed to cool to room temperature and was refrigerated overnight. The crystals that formed were filtered, dried, and recrystallized from water to obtain 7.84 grams of 3-methyl-2-oxobenzimidazole, melting point 188°-189° C.

Workup

  1. customwas prepared
  2. temperatureThe reaction mixture then was cooled to about 80° C.
  3. temperaturethe mixture was refluxed for 20 minutes
  4. filtrationwas filtered while hot
  5. temperatureto cool to room temperature
  6. waitwas refrigerated overnight
  7. customThe crystals that formed
  8. filtrationwere filtered
  9. customdried
  10. customrecrystallized from water

Sources & evidence

ORD record
ord-a99d862220884105b469e31ae9b6c1ad
Source dataset
uspto-grants-1977_12
Patent number
US04061861

Reaction notes

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