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

HRID 339423Notes

Reaction equation

HRID 339423 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>>[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

3

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

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 a reaction mass was poured into a mixture of ice and water (2 kg). Precipitate was filtered out. Filtrate was diluted with water (1.25 1) and ammonia solution (˜800 ml), after that pH was adjusted to 5.6 with ammonia solution. Precipitate was filtered and rinsed with water. Yield was 39.5 g (84%).

Workup

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

Sources & evidence

ORD record
ord-ac95ae08636d4fbd8a4b9628e83a6bfd
Source dataset
uspto-grants-2014_11
Patent number
US08895118B2

Reaction notes

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