Phosphorus oxychloride → Isopropyl [2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]acetate

HRID 1698573Notes

Reaction equation

HRID 1698573 reaction equation
[CH:1]([O:4][C:5](=[O:23])[CH2:6][N:7]1[C:11]2[C:12]([CH:17]([CH2:20][CH3:21])[CH2:18][CH3:19])=[CH:13][CH:14]=[C:15]([Cl:16])[C:10]=2[NH:9][C:8]1=O)([CH3:3])[CH3:2].P(Cl)(Cl)([Cl:26])=O>>[CH:1]([O:4][C:5](=[O:23])[CH2:6][N:7]1[C:11]2[C:12]([CH:17]([CH2:20][CH3:21])[CH2:18][CH3:19])=[CH:13][CH:14]=[C:15]([Cl:16])[C:10]=2[N:9]=[C:8]1[Cl:26])([CH3:3])[CH3:2]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 86632856Isopropyl [4-chloro-7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]acetate

Product 1

HCID 86632857Isopropyl [2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazol-1-yl]acetateYield 97.2%

Conditions

Temperature
100 °C

Procedure

A mixture of isopropyl[4-chloro-7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]acetate (3.73 g, 11.0 mmol) and phosphorus oxychloride (20 mL) was stirred at 100° C. for 48 hours. After cooling, phosphorus oxychloride was evaporated in vacuo. The residue was neutralized with saturated aqueous sodium hydrogen carbonate and extracted with ethyl acetate (X2). The combined organic layer was washed with brine (X1), dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 5-15% ethyl acetate/hexane gradient mixture to give 3.82 g (10.7 mmol, 97.2%) of the title compound as an oil.

Workup

  1. temperatureAfter cooling
  2. customphosphorus oxychloride was evaporated in vacuo
  3. extractionextracted with ethyl acetate (X2)
  4. washThe combined organic layer was washed with brine (X1)
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by silica gel column chromatography
  8. washeluting with a 5-15% ethyl acetate/hexane gradient mixture

Sources & evidence

ORD record
ord-73701df0537a43ceb970a029086bc07a
Source dataset
uspto-grants-2012_04
Patent number
US08163935B2

Reaction notes

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