Formic Acid → 2-(2,4-Difluorophenyl)cyclopentanone

HRID 475812Notes

Reaction equation

HRID 475812 reaction equation
[CH:1]([OH:3])=O.OO.[C:6]1([C:11]2[CH:16]=[CH:15][C:14]([F:17])=[CH:13][C:12]=2[F:18])C[CH2:9][CH2:8][CH:7]=1>>[F:18][C:12]1[CH:13]=[C:14]([F:17])[CH:15]=[CH:16][C:11]=1[CH:6]1[CH2:7][CH2:8][CH2:9][C:1]1=[O:3]

Participants

4

Reactant 3

HCID 284Formic AcidHCID 784Hydrogen PeroxideHCID 580757581-(Cyclopent-1-en-1-yl)-2,4-difluorobenzene

Product 1

HCID 580754402-(2,4-Difluorophenyl)cyclopentanoneYield 45.5%

Conditions

Temperature
40 °C

Procedure

A mixture of 90% formic acid (26.4 mL, 689 mmol) and 30% hydrogen peroxide (6.0 mL, 39.2 mmol) was warmed at 40° C. for 10 min. The resulting solution was carefully added to 1-cyclopentenyl-2,4-difluorobenzene (7.064 g, 39.2 mmol) under stirring. The two-phase system was initially stirred at room temperature. After a certain period of time, a spontaneous exothermic reaction took place, and the temperature rose to about 50° C. The reaction mixture was stirred at room temperature for 2 h. The reaction mixture was quenched by careful addition of a saturated sodium bicarbonate solution. Ether was added and the content of the separatory funnel was vigorously shaken. The organic layer was separated and the aqueous layer was extracted with ether. The combined organic extracts were dried over anhydrous magnesium sulfate and filtered. The solvent was removed in vacuum and the residue was purified by column chromatography on silica gel to give 2-(2,4-difluorophenyl)cyclopentanone (3.503 g, 17.85 mmol, 45.5% yield) as colorless oil. LC-MS (M+H)+=195.2. 1H NMR (500 MHz, CDCl3) δ ppm 7.08 (1H, td, J=8.4, 6.4 Hz), 6.76-6.86 (2H, m), 3.42 (1H, dd, J=12.2, 8.9 Hz), 2.42-2.53 (2H, m), 2.28-2.39 (1H, m), 2.13-2.23 (1H, m), 1.86-2.10 (2H, m).

Workup

  1. stirringThe two-phase system was initially stirred at room temperature
  2. waitAfter a certain period of time
  3. customa spontaneous exothermic reaction
  4. customrose to about 50° C
  5. stirringThe reaction mixture was stirred at room temperature for 2 h
  6. customThe reaction mixture was quenched by careful addition of a saturated sodium bicarbonate solution
  7. additionEther was added
  8. stirringthe content of the separatory funnel was vigorously shaken
  9. customThe organic layer was separated
  10. extractionthe aqueous layer was extracted with ether
  11. dry with materialThe combined organic extracts were dried over anhydrous magnesium sulfate
  12. filtrationfiltered
  13. customThe solvent was removed in vacuum
  14. customthe residue was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-5f8d23e867bf4b9fa101242d250dd17a
Source dataset
uspto-grants-2014_01
Patent number
US08637525B2

Reaction notes

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