Ethylene Glycol → (1-Allylcyclohexyl)benzene

HRID 71245Notes

Reaction equation

HRID 71245 reaction equation
[CH2:1]([C:4]1([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH2:9][CH2:8][CH2:7][CH2:6][C:5]1=O)[CH:2]=[CH2:3].C(O)CO.NN.[OH-].[K+]>>[CH2:1]([C:4]1([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH2:9][CH2:8][CH2:7][CH2:6][CH2:5]1)[CH:2]=[CH2:3]

Participants

5

Reactant 4

HCID 174Ethylene GlycolHCID 9321HydrazineHCID 14797Potassium HydroxideHCID 130232142-Allyl-2-phenylcyclohexanone

Product 1

HCID 86688202(1-Allylcyclohexyl)benzeneYield 44.8%

Conditions

Temperature
100 °C

Procedure

To a solution of 2-allyl-2-phenylcyclohexanone (1.97 g, 9.19 mmol) in ethylene glycol (8 mL, 143 mmol) were added hydrazine (0.8 mL, 25.5 mmol) and potassium hydroxide (1.547 g, 27.6 mmol), and the mixture was stirred at 100° C. for 1 hr and refluxed in a 180° C. oil bath for 2.5 hrs. TLC showed that the hydrazone formation nearly complete. Then the excess hydrazine and water were distilled out in a 200° C. oil bath, and it was continued to heat at the same temperature for 4 hrs. After cooling to room temp it was added to ether and washed with water and brine. The combined aqueous layers were back-extracted with ether (2×) and combined. Dried over Na2SO4 and evaporated to give an oily residue. It was purified by Combiflash (80 g silica gel) eluting with hexane followed by 5:95 EtOAc-hexane to give product (825 mg). 1H NMR (400 MHz, CCl3D) δ ppm 7.31 (4H, d, J=4.39 Hz), 7.17 (1H, dq, J=4.39, 4.25 Hz), 5.32-5.45 (1H, m), 4.89 (1H, s), 4.83-4.87 (1H, m), 2.26 (2H, d, J=7.47 Hz), 2.07 (2H, dd, J=13.84, 6.59 Hz), 1.33-1.63 (8H, m).

Workup

  1. temperaturerefluxed in a 180° C. oil bath for 2.5 hrs
  2. distillationThen the excess hydrazine and water were distilled out in a 200° C. oil bath
  3. temperatureto heat at the same temperature for 4 hrs
  4. temperatureAfter cooling to room temp it
  5. additionwas added to ether
  6. washwashed with water and brine
  7. extractionThe combined aqueous layers were back-extracted with ether (2×)
  8. dry with materialDried over Na2SO4
  9. customevaporated
  10. customto give an oily residue
  11. customIt was purified by Combiflash (80 g silica gel)
  12. washeluting with hexane

Sources & evidence

ORD record
ord-37cd9b4ce07a45d9aa86f3854b8f6044
Source dataset
uspto-grants-2014_09
Patent number
US08822510B2

Reaction notes

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