Hydrochloric Acid → 7-(1-Ethylprop-1-en-1-yl)-1-methyl-4-(trifluoromethyl)-1,3-dihydro-2H-benzimidazol-2-one

HRID 1698604Notes

Reaction equation

HRID 1698604 reaction equation
[CH3:1][N:2]1[C:6]2[C:7]([C:15](OC)=O)=[CH:8][CH:9]=[C:10]([C:11]([F:14])([F:13])[F:12])[C:5]=2[NH:4][C:3]1=[O:19].[CH2:20]([Mg]Br)[CH3:21].[CH2:24](OCC)[CH3:25].Cl>O1CCCC1.O.CO>[CH2:24]([C:15]([C:7]1[C:6]2[N:2]([CH3:1])[C:3](=[O:19])[NH:4][C:5]=2[C:10]([C:11]([F:14])([F:13])[F:12])=[CH:9][CH:8]=1)=[CH:20][CH3:21])[CH3:25]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 3283Diethyl EtherHCID 67273045methyl 3-methyl-2-oxo-7-(trifluoromethyl)-2,3-dihydro-1H-benzimidazole-4-carboxylateHCID 178418443HCID 178418443, compound

Product 1

HCID 672729457-(1-Ethylprop-1-en-1-yl)-1-methyl-4-(trifluoromethyl)-1,3-dihydro-2H-benzimidazol-2-one

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
45 °C

Procedure

To an ice-cooled solution of, methyl 3-methyl-2-oxo-7-(trifluoromethyl)-2,3-dihydro-1H-benzimidazole-4-carboxylate (2.80 g, 10.2 mmol) in tetrahydrofuran (30 ml) was added a solution of 3M ethylmagnesium bromide in diethylether (13.6 ml, 40.8 mmol) dropwise and stirred at 45° C. for 16 h. Methanol and water were carefully added to decompose excess reagent. 2N hydrochloric acid was added and extracted with ethyl acetate. The extracts were washed with aqueous saturated sodium bicarbonate and water, dried over magnesium sulfate and concentrated in vacuo. Ethanol (40 ml) and conc. hydrochloric acid (10 ml) were added to the residue and the resulting mixture was heated at 80° C. for 6 h. The reaction mixture was concentrated in vacuo. Aqueous saturated sodium bicarbonate was added to the residue and extracted with ethyl acetate. The extracts were washed with water, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by chromatography on silica gel with a 20% ethyl acetate/n-hexane to give 609 mg (2.14 mmol, 21%, cis/trans=3/1) of the title compound as a white powder.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe extracts were washed with aqueous saturated sodium bicarbonate and water
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated in vacuo
  5. additionEthanol (40 ml) and conc. hydrochloric acid (10 ml) were added to the residue
  6. temperaturethe resulting mixture was heated at 80° C. for 6 h
  7. concentrationThe reaction mixture was concentrated in vacuo
  8. additionAqueous saturated sodium bicarbonate was added to the residue
  9. extractionextracted with ethyl acetate
  10. washThe extracts were washed with water
  11. dry with materialdried over magnesium sulfate
  12. concentrationconcentrated in vacuo
  13. customThe residue was purified by chromatography on silica gel with a 20% ethyl acetate/n-hexane

Sources & evidence

ORD record
ord-1f10379d390943fca9388ebb90056624
Source dataset
uspto-grants-2012_04
Patent number
US08163935B2

Reaction notes

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