Propylene Glycol → 1,3-Dioxolane, 2,4-dimethyl-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-

HRID 1091004Notes

Reaction equation

HRID 1091004 reaction equation
C([O-])([O-])OCC.[C:7]([C:10]1[CH:11]=[C:12]2[C:17](=[CH:18][CH:19]=1)[C:16]([CH3:21])([CH3:20])[CH2:15][CH2:14][C:13]2([CH3:23])[CH3:22])(=[O:9])[CH3:8].[CH2:24](O)[CH:25]([OH:27])[CH3:26]>C(Cl)(=O)C.C1(C)C=CC(S(O)(=O)=O)=CC=1.C(O)C.C1(C)C=CC=CC=1>[CH3:8][C:7]1([C:10]2[CH:11]=[C:12]3[C:17](=[CH:18][CH:19]=2)[C:16]([CH3:21])([CH3:20])[CH2:15][CH2:14][C:13]3([CH3:23])[CH3:22])[O:27][CH:25]([CH3:26])[CH2:24][O:9]1

Participants

8

Reactant 3

HCID 1030Propylene GlycolHCID 27475621-(5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)ethan-1-oneHCID 53630039Ethylorthoformate

Product 1

HCID 30342781,3-Dioxolane, 2,4-dimethyl-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-Yield 63.2%

Reagents, catalysts & solvents 4

HCID 6101p-Toluenesulfonic acidCatalystHCID 6367Acetyl chlorideCatalystHCID 702EthanolSolvent2×HCID 1140TolueneSolvent

Procedure

Acetyl chloride (0.15 g) is added dropwise at room temperature to a mixture of 52.5 g (0.35 mol) of ethyl orthoformate, 30 g (0.13 mol) of 6-acetyl-1,1,4,4-tetra-methyl-tetralin and 18 ml of ethanol. The reaction is slightly exothermic, which results in a temperature increase from 20° C. to 28° C. The mixture is stirred at this temperature for 2 hours. The excess ethyl orthoformate and ethanol are removed by vacuum distillation (120° C./ 100 mm Hg). After this time the reaction mixture is cooled and 50 ml of toluene, 22.5 g (0.29 mol) of propylene glycol and 0.3 g of p-toluenesulphonic acid are added rapidly. The mixture is stirred at 85° C. to 90° C. for 2 1/2 hours. The ethanol which is formed is removed by distillation. Thereupon, the residual mixture is neutralized by the addition of a 10% solution of potassium hydroxide in ethanol, filtered and the filtrate is evaporated. Crude 2-dimethyl-2-(1,1,4,4-tetramethyl-tetralin-6-yl)-1,3-dioxolane is obtained. The product is purified by vacuum distillation and there are obtained 23.7 g of pure product. The boiling point of the pure product is 112° C. at 0.45 mmHg.

Workup

  1. customwhich results in a temperature
  2. temperatureincrease from 20° C. to 28° C
  3. customThe excess ethyl orthoformate and ethanol are removed by vacuum distillation (120° C./ 100 mm Hg)
  4. temperatureAfter this time the reaction mixture is cooled
  5. stirringThe mixture is stirred at 85° C. to 90° C. for 2 1/2 hours
  6. customis removed by distillation
  7. additionThereupon, the residual mixture is neutralized by the addition of a 10% solution of potassium hydroxide in ethanol
  8. filtrationfiltered
  9. customthe filtrate is evaporated
  10. customCrude 2-dimethyl-2-(1,1,4,4-tetramethyl-tetralin-6-yl)-1,3-dioxolane is obtained
  11. distillationThe product is purified by vacuum distillation and there

Sources & evidence

ORD record
ord-e9b646521d2c44fca9cc5f704350d6b9
Source dataset
uspto-grants-1992_01
Patent number
US05084440

Reaction notes

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