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

HRID 2292716Notes

Reaction equation

HRID 2292716 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)).

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-f8fa1af3361e4ffabcd94cd6671d0d4a
Source dataset
uspto-grants-1997_11
Patent number
US05684029

Reaction notes

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