Butyryl chloride → Methyl-2-n-propyl-benzimidazole-5-carboxylate

HRID 1081890Notes

Reaction equation

HRID 1081890 reaction equation
Cl.Cl.[NH2:3][C:4]1[CH:5]=[C:6]([CH:11]=[CH:12][C:13]=1[NH2:14])[C:7]([O:9][CH3:10])=[O:8].[C:15](Cl)(=O)[CH2:16][CH2:17][CH3:18]>P(Cl)(Cl)(Cl)=O>[CH3:10][O:9][C:7]([C:6]1[CH:11]=[CH:12][C:13]2[N:14]=[C:15]([CH2:16][CH2:17][CH3:18])[NH:3][C:4]=2[CH:5]=1)=[O:8]

Participants

4

Reactant 2

HCID 8855Butyryl chlorideHCID 18174510Methyl 3,4-diaminobenzoate dihydrochloride

Product 1

HCID 10398475Methyl-2-n-propyl-benzimidazole-5-carboxylate

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A solution of 23.9 g (100 mMol) of methyl 3,4-diaminobenzoate dihydrochloride and 11.7 g (110 mMol) of butyric acid chloride in 100 ml of phosphorus oxychloride is refluxed for 2 hours. Then about 80 ml of phosphorus oxychloride are distilled off and the residue is mixed with about 150 ml of water. The oily crude product precipitated is extracted three times with 50 ml of ethyl acetate and after evaporation purified by column chromatography (600 g of silica gel; eluant:methylene chloride/methanol (30:1)). Yield: 15.0 g of oil (69% of theory)

Workup

  1. distillationThen about 80 ml of phosphorus oxychloride are distilled off
  2. additionthe residue is mixed with about 150 ml of water
  3. customThe oily crude product precipitated
  4. extractionis extracted three times with 50 ml of ethyl acetate
  5. customafter evaporation
  6. custompurified by column chromatography (600 g of silica gel; eluant:methylene chloride/methanol (30:1))

Sources & evidence

ORD record
ord-c4b569340a724837be128581a3af2268
Source dataset
uspto-grants-1996_12
Patent number
US05587393

Reaction notes

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