Isoprene → 1-(4,6,6-Trimethylcyclohex-3-en-1-yl)ethan-1-one

HRID 1449320Notes

Reaction equation

HRID 1449320 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[O:5]=[C:6]([CH:8]=[C:9]([CH3:11])[CH3:10])[CH3:7].[CH2:12]=[CH:13][C:14](=[CH2:16])[CH3:15]>C1C=CC=CC=1>[CH3:16][C:14]1[CH2:15][C:9]([CH3:11])([CH3:10])[CH:8]([C:6](=[O:5])[CH3:7])[CH2:12][CH:13]=1

Participants

5

Reactant 3

HCID 6557IsopreneHCID 8858Mesityl oxideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 205472391-(4,6,6-Trimethylcyclohex-3-en-1-yl)ethan-1-oneYield 76.3%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent2×

Procedure

A flask is charged with 63 g of aluminium chloride and 2160 ml of anhydrous benzene. The apparatus is filled with nitrogen and 441 g of mesityl oxide are added, whilst stirring and maintaining the temperature of the mixture at +15°. The mixture is then left for 30 minutes at this temperature, whilst stirring. 1224 g of isoprene dissolved in 1800 ml of anhydrous benzene are then added in the course of 1 hour at +15°. Reaction is then effected for 20 hours at 16° followed by 6 hours at +25°, with stirring. The contents of the flask are then transferred to a separating funnel and the product is washed twice with 500 ml of 10% hydrochloric acid, once with 500 ml of water, once with 500 ml of a 9% solution of sodium bicarbonate and twice with 500 ml of water. The benzene is distilled off on a water bath, finally, under a pressure of 30 mm of mercury. 1070 g of crude product are obtained, which are purified in a Vigreux flask under a pressure of 1 mm of mercury. 560 g of 1,5,5-trimethyl-4-acetyl-cyclohex-1-ene (76.3%) are obtained, having the following physical properties:

Workup

  1. additionare added
  2. temperaturemaintaining the temperature of the mixture at +15°
  3. stirringwhilst stirring
  4. additionare then added in the course of 1 hour at +15°
  5. customReaction
  6. waitis then effected for 20 hours at 16°
  7. waitfollowed by 6 hours at +25°
  8. stirringwith stirring
  9. customThe contents of the flask are then transferred to a separating funnel
  10. washthe product is washed twice with 500 ml of 10% hydrochloric acid, once with 500 ml of water, once with 500 ml of a 9% solution of sodium bicarbonate and twice with 500 ml of water
  11. distillationThe benzene is distilled off on a water bath
  12. custom1070 g of crude product are obtained
  13. customwhich are purified in a Vigreux flask under a pressure of 1 mm of mercury

Sources & evidence

ORD record
ord-f373357e1a0748dfb4887682897ae4e8
Source dataset
uspto-grants-1980_02
Patent number
US04190561

Reaction notes

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