Phosphorus oxychloride → 2-Chloro-7-(1-ethylpropyl)-4-methoxy-1-methyl-1H-benzimidazole

HRID 1698561Notes

Reaction equation

HRID 1698561 reaction equation
[CH2:1]([CH:3]([C:6]1[C:11]2[N:12]([CH3:16])[C:13](=O)[NH:14][C:10]=2[C:9]([O:17][CH3:18])=[CH:8][CH:7]=1)[CH2:4][CH3:5])[CH3:2].P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:13]1[N:12]([CH3:16])[C:11]2[C:6]([CH:3]([CH2:4][CH3:5])[CH2:1][CH3:2])=[CH:7][CH:8]=[C:9]([O:17][CH3:18])[C:10]=2[N:14]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 672729917-(1-Ethylpropyl)-4-methoxy-1-methyl-1,3-dihydro-2H-benzimidazol-2-one

Product 1

HCID 672730962-Chloro-7-(1-ethylpropyl)-4-methoxy-1-methyl-1H-benzimidazoleYield 60%

Conditions

Temperature
110 °C

Procedure

A mixture of 7-(1-ethylpropyl)-4-methoxy-1-methyl-1,3-dihydro-2H-benzimidazol-2-one (190 mg, 0.765 mmol) in phosphorous oxychloride (2.14 mL) was stirred at 110° C. for 6 h. The reaction was allowed to cool to room temperature and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with aqueous sodium bicarbonate and brine. The organic layer was dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate 10:1-1:1) and crystallized from ethyl acetate/n-hexane to afford the title compound as colorless crystals (123 mg, 60%).

Workup

  1. temperatureto cool to room temperature
  2. concentrationconcentrated in vacuo
  3. dissolutionThe residue was dissolved in ethyl acetate
  4. washwashed with aqueous sodium bicarbonate and brine
  5. dry with materialThe organic layer was dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate 10:1-1:1)
  9. customcrystallized from ethyl acetate/n-hexane

Sources & evidence

ORD record
ord-051f5c5729ba4a7594f3af1c0fe654fd
Source dataset
uspto-grants-2012_04
Patent number
US08163935B2

Reaction notes

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