Phosphorus oxychloride → 5-Methylbenzimidazolone

HRID 1097127

Reaction equation

HRID 1097127 reaction equation
[O:1]=[C:2]1[NH:6][C:5]2[CH:7]=[C:8]([C:11](OC)=O)[CH:9]=[CH:10][C:4]=2[NH:3]1.P(Cl)(Cl)(Cl)=O>O>[CH3:11][C:8]1[CH:9]=[CH:10][C:4]2[NH:3][C:2](=[O:1])[NH:6][C:5]=2[CH:7]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 10352553methyl 2-oxo-2,3-dihydro-1H-1,3-benzodiazole-5-carboxylate

Product 1

HCID 2231345-Methylbenzimidazolone

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Methyl 2-oxo-2,3-dihydro-1H-benzimidazole-6-carboxylate (43 g, 0.22 mol) was charged into phosphorus oxychloride (286 ml). Dry hydrogen chloride was bubbled through the boiling reaction mass for 12 hours. After cooling reaction mass was poured in mixture of ice and water (2 kg). Precipitate was filtered out. Filtrate was diluted with water (1.25 litres) and ammonia solution (˜800 ml). After that pH was adjusted to 5.6 with ammonia solution. Precipitate was filtered and rinsed with water. Yield 39.5 g (84%).

Workup

  1. customDry hydrogen chloride was bubbled through the boiling reaction mass for 12 hours
  2. temperatureAfter cooling
  3. customreaction mass
  4. filtrationPrecipitate was filtered out
  5. additionFiltrate was diluted with water (1.25 litres) and ammonia solution (˜800 ml)
  6. filtrationPrecipitate was filtered
  7. washrinsed with water

Sources & evidence

ORD record
ord-32acb0734e564e3ab0a4e2867ae69876
Source dataset
uspto-grants-2012_03
Patent number
US08142863B2

Linked notes

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