Trifluoroacetic acid → 4-Cyclopent-1-en-1-ylbenzaldehyde

HRID 456285

Reaction equation

HRID 456285 reaction equation
C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][C:10]([CH:13]([O:16]C)OC)=[CH:9][CH:8]=1.[C:18]1(=O)[CH2:22][CH2:21][CH2:20][CH2:19]1.FC(F)(F)C(O)=O>C1COCC1.C(OCC)(=O)C.ClCCl.O>[C:18]1([C:7]2[CH:8]=[CH:9][C:10]([CH:13]=[O:16])=[CH:11][CH:12]=2)[CH2:22][CH2:21][CH2:20][CH:19]=1

Participants

8

Reactant 4

HCID 6422Trifluoroacetic acidHCID 8452CyclopentanoneHCID 6883421-Bromo-4-(dimethoxymethyl)benzeneHCID 178418339Butyllithium

Product 1

HCID 866700384-Cyclopent-1-en-1-ylbenzaldehydeYield 90%

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolventHCID 21908982Water methylene chlorideSolvent

Procedure

n-Butyllithium (7.2 mL, 1.56 M hexane solution, 11.2 mmol) was added to a solution in THF (25 mL) of 1-bromo-4-(dimethoxymethyl)benzene (2.29 g, 9.91 mmol) at −78° C. The mixture was stirred at the same temperature for 2 hours, and then cyclopentanone (1.34 mL, 15.1 mmol) was added thereto. The resulting mixture was heated to room temperature and then stirred for 1 hour. The reaction was terminated by adding a saturated ammonium chloride aqueous solution, and an extraction with ethyl acetate was conducted three times. The resulting organic layers were washed with water and saturated brine and then dried over anhydrous magnesium sulfate. The solvent was evaporated, and the resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate, 5:1, v/v) to give an oily compound. Trifluoroacetic acid (9 mL) was added to a dichloromethane-water (9.1 mL, 100:1, v/v) mixture solution containing the resulting oily compound at room temperature, and the mixture was continuously stirred for 20 minutes. The solvent was evaporated, and the resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate, 10:1, v/v) to give 1.18 g of the title compound (light brown crystalline solid, yield: 90%).

Workup

  1. stirringstirred for 1 hour
  2. customThe reaction was terminated
  3. additionby adding a saturated ammonium chloride aqueous solution
  4. extractionan extraction with ethyl acetate
  5. washThe resulting organic layers were washed with water and saturated brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. customThe solvent was evaporated
  8. customthe resulting residue was purified by silica gel column chromatography (hexane
  9. customethyl acetate, 5:1, v/v) to give an oily compound
  10. additionv/v) mixture solution containing the resulting oily compound at room temperature
  11. stirringthe mixture was continuously stirred for 20 minutes
  12. customThe solvent was evaporated
  13. customthe resulting residue was purified by silica gel column chromatography (hexane

Sources & evidence

ORD record
ord-5338b50d49aa4c3185dea69667ce3982
Source dataset
uspto-grants-2013_07
Patent number
US08497397B2

Linked notes

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