Phosphorus oxychloride → Methyl 2-chloro-1H-benzo[d]imidazole-5-carboxylate

HRID 1965223Notes

Reaction equation

HRID 1965223 reaction equation
O=[C:2]1[NH:6][C:5]2[CH:7]=[C:8]([C:11]([O:13][CH3:14])=[O:12])[CH:9]=[CH:10][C:4]=2[NH:3]1.P(Cl)(Cl)([Cl:17])=O>O>[Cl:17][C:2]1[NH:6][C:5]2[CH:7]=[C:8]([C:11]([O:13][CH3:14])=[O:12])[CH:9]=[CH:10][C:4]=2[N:3]=1

Participants

4

Reactant 2

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

Product 1

HCID 11543028Methyl 2-chloro-1H-benzo[d]imidazole-5-carboxylate

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 l) and ammonia solution (˜800 ml). After that pH was adjusted to 5.6 with use of 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 l) and ammonia solution (˜800 ml)
  6. filtrationPrecipitate was filtered
  7. washrinsed with water

Sources & evidence

ORD record
ord-29519c791d434db0a19a91ee3483d565
Source dataset
uspto-grants-2013_04
Patent number
US08416376B2

Reaction notes

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