Acetic Acid → Phenol, 4-(1-methylethenyl)-, acetate

HRID 1834489Notes

Reaction equation

HRID 1834489 reaction equation
[C:1]([C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1)([CH3:3])=[CH2:2].S(=O)(=O)(O)O.[C:16](O)(=[O:18])[CH3:17]>C(OC(=O)C)(=O)C>[C:16]([O:10][C:7]1[CH:8]=[CH:9][C:4]([C:1]([CH3:3])=[CH2:2])=[CH:5][CH:6]=1)(=[O:18])[CH3:17]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 1118Sulfuric AcidHCID 584247p-Isopropenylphenol

Product 1

HCID 12250212Phenol, 4-(1-methylethenyl)-, acetate

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Conditions

Temperature
200 °C

Procedure

134 g of dimeric p-isopropenyl phenol are dissolved under nitrogen in 150 g of acetic acid anhydride, followed by the addition of 0.5 g of concentrated sulphuric acid. The reaction begins with a slight heat effect under which the temperature of the reaction mixture rises to around 50° C and then falls again. When the reaction temperature has fallen to around 30° C, the reaction mixture is slowly heated until, finally, acetic acid distils off under normal pressure. The temperature is regulated in such a way that distillation is continuous. When no more acetic acid distils over, the remaining acetic acid and the excess acetic acid anhydride are distilled off in a water jet vacuum, after which the reaction mixture is cooled. Another 5 g of concentrated sulphuric acid are then added, followed by heating in a high vacuum until p-acetoxy-α-methyl styrene distils off. The temperature of the reaction mixture is regulated in such a way that the reaction mixture distils off continuously; it is in the range from 70° to 120° C and is ultimately increased to 200° C. The reaction product which has distilled over is then redistilled; 119 g (68% of the theoretical) of p-acetoxy-α-methyl styrene are obtained in the boiling range from 80° to 82° C/0.1 Torr.

Workup

  1. customrises to around 50° C
  2. customhas fallen to around 30° C
  3. customdistils off under normal pressure
  4. distillationthat distillation
  5. customWhen no more acetic acid distils over, the remaining acetic acid
  6. distillationthe excess acetic acid anhydride are distilled off in a water jet vacuum
  7. temperatureafter which the reaction mixture is cooled
  8. additionAnother 5 g of concentrated sulphuric acid are then added
  9. temperatureby heating in a high vacuum until p-acetoxy-α-methyl styrene
  10. customdistils off
  11. customdistils off continuously
  12. customis in the range from 70° to 120° C
  13. distillationThe reaction product which has distilled
  14. distillationover is then redistilled

Sources & evidence

ORD record
ord-cebb551877044224ad18710e4aa77426
Source dataset
uspto-grants-1978_01
Patent number
US04070392

Reaction notes

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