Hydrochloric Acid → 4-(4-(2-Fluoroethyl)cyclohexyl)-1-(2-(4-trifluoromethoxyphenyl)ethyl)-1-cyclohexene

HRID 1941030Notes

Reaction equation

HRID 1941030 reaction equation
[F:1][C:2]([F:14])([F:13])[O:3][C:4]1[CH:9]=[CH:8][C:7]([CH2:10][CH2:11]Br)=[CH:6][CH:5]=1.[F:15][CH2:16][CH2:17][CH:18]1[CH2:23][CH2:22][CH:21]([CH:24]2[CH2:29][CH2:28][C:27](=O)[CH2:26][CH2:25]2)[CH2:20][CH2:19]1.Cl>CCOCC>[F:15][CH2:16][CH2:17][CH:18]1[CH2:19][CH2:20][CH:21]([CH:24]2[CH2:29][CH2:28][C:27]([CH2:11][CH2:10][C:7]3[CH:8]=[CH:9][C:4]([O:3][C:2]([F:14])([F:13])[F:1])=[CH:5][CH:6]=3)=[CH:26][CH2:25]2)[CH2:22][CH2:23]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 153901221-(2-Bromoethyl)-4-(trifluoromethoxy)benzeneHCID 214594604-(4-(2-Fluoroethyl)cyclohexyl)cyclohexanone

Product 1

HCID 214594534-(4-(2-Fluoroethyl)cyclohexyl)-1-(2-(4-trifluoromethoxyphenyl)ethyl)-1-cyclohexeneYield 46.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Conditions

Temperature
0 °C

Procedure

A Grignard reagent prepared from the above 2-(4-trifluoromethoxyphenyl)bromoethane (7.0 g, 30.3 mmol) and dried Mg (0.74 g, 30.4 mmol) in an ether solvent (40 ml) was cooled down to 0° C., followed by dropwise adding thereto a 30 ml ether solution of 4-(4-(2-fluoroethyl)cyclohexyl)cyclohexanone (2.2 g, 9.7 mmol) prepared at the third step, stirring the mixture at 0° C. for 3 hours, adding 6N HCl to the reaction solution, extracting the resulting product with toluene, washing the extraction solution successively with a saturated aqueous solution of sodium bicarbonate and water, drying over magnesium sulfate, distilling off the solvent, adding toluene (100 ml) and Amberlist (500 mg) to the resulting yellow oily substance, refluxing the mixture for 4 hours, while removing water formed by the reaction by means of Dean-Stark, filtering off Amberlist, distilling off the solvent, purifying the residue according to column chromatography treatment using toluene as a developing solvent, on silica gel, to isolate 4-(4-(2-fluoroethyl)cyclohexyl)-1-(2-(4-trifluoromethoxyphenyl)ethyl)-1-cyclohexene (1.8 g, 4.5 mmol), hydrogenating this product (1.2 g, 3.0 mmol) in the presence of 5% Pd/C catalyst (0.12 g) in ethanol solution, filtering off the catalyst, distilling off the solvent under reduced pressure, and recrystallizing the residue, to isolate only trans-form of colorless 1-(2-(4-(4-(2-fluoroethyl)-cyclohexyl)cyclohexyl)ethyl-4-trifluoromethoxybenzene (0.37 g, 0.90 mmol) exhibiting smectic phase. The yield of this product from 4-(4-(2-fluoroethyl)chclohexyl)cyclohexanone was 9.3%.

Workup

  1. additionby dropwise adding
  2. extractionextracting the resulting product with toluene
  3. washwashing the extraction solution successively with a saturated aqueous solution of sodium bicarbonate and water
  4. dry with materialdrying over magnesium sulfate
  5. distillationdistilling off the solvent
  6. additionadding toluene (100 ml) and Amberlist (500 mg) to the resulting yellow oily substance
  7. temperaturerefluxing the mixture for 4 hours
  8. customwhile removing water
  9. customformed by the reaction by means of Dean-Stark
  10. filtrationfiltering off Amberlist
  11. distillationdistilling off the solvent
  12. custompurifying the residue

Sources & evidence

ORD record
ord-7d89458af1124df9a1edd0007d9e4d3d
Source dataset
uspto-grants-1997_12
Patent number
US05702641

Reaction notes

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