Phosphorus oxychloride → 1-Allyl-2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazole

HRID 1628459Notes

Reaction equation

HRID 1628459 reaction equation
[CH2:1]([N:4]1[C:8]2[C:9]([CH:14]([CH2:17][CH3:18])[CH2:15][CH3:16])=[CH:10][CH:11]=[C:12]([Cl:13])[C:7]=2[NH:6][C:5]1=O)[CH:2]=[CH2:3].P(Cl)(Cl)([Cl:22])=O>C(OCC)(=O)C>[CH2:1]([N:4]1[C:8]2[C:9]([CH:14]([CH2:17][CH3:18])[CH2:15][CH3:16])=[CH:10][CH:11]=[C:12]([Cl:13])[C:7]=2[N:6]=[C:5]1[Cl:22])[CH:2]=[CH2:3]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 687711291-Allyl-4-chloro-7-(1-ethylpropyl)-1,3-dihydro-2H-benzimidazol-2-one

Product 1

HCID 687711711-Allyl-2,4-dichloro-7-(1-ethylpropyl)-1H-benzimidazoleYield 95%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

A solution of 1-allyl-4-chloro-7-(1-ethylpropyl)-1,3-dihydro-2H-benzimidazol-2-one (9.80 g, 35.1 mmol) in phosphoryl chloride (35 mL) was stirred at 100° C. for 2 hr. The mixture was concentrated in vacuo to give a residue which was dissolved in ethyl acetate, washed with aqueous sodium bicarbonate and brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with a 5-20% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound (9.90 g, 33.3 mmol, 95%) as a colorless solid.

Workup

  1. concentrationThe mixture was concentrated in vacuo
  2. customto give a residue which
  3. washwashed with aqueous sodium bicarbonate and brine
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by flash chromatography on silica gel eluting with a 5-20% ethyl acetate/n-hexane gradient mixture
  7. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-9f606552d2164a9f9fad5f4a0b3e68bc
Source dataset
uspto-grants-2014_07
Patent number
US08785460B2

Reaction notes

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