Sulfuric Acid → Alpha-Methylstyrene

HRID 328171Notes

Reaction equation

HRID 328171 reaction equation
[O-]O.[C:3]1([CH:9]([CH3:11])[CH3:10])[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.S(=O)=[O:13].S(=O)(=O)(O)O>O>[CH3:10][C:9]([CH3:11])([C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1)[OH:13].[CH3:11][C:9]([C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1)=[CH2:10]

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 1119Sulfur DioxideHCID 53627471Cumen hydroperoxide3×

Product 2

HCID 7407Alpha-MethylstyreneHCID 120532-Phenyl-2-propanol

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

In accordance with the present invention, this is accomplished by an improvement in the process for obtaining phenol from cumene hydroperoxide, which has been obtained by liquid-phase oxidation of cumene with molecular oxygen, which involves forming a reaction mixture by continuously feeding the cumene hydroperoxide into a decomposer wherein the incoming hydroperoxide is diluted by cumene hydroperoxide decomposition products previously formed therein, maintaining the reaction mixture at elevated temperature, feeding to the reaction mixture a decomposition catalyst selected from the group consisting of sulfur dioxide and sulfuric acid, withdrawing reaction mixture from the decomposer, removing the decomposition catalyst from the product withdrawn from the decomposer, and fractionally distilling the resulting organic products to separately recover an acetone fraction, a phenol fraction and one or more by-product fractions, which improvement comprises, in combination (a) maintaining the reaction mixture in the decomposer at a temperature in the range of from 65° to 105° C.; (b) feeding the decomposition catalyst to the reaction mixture in amount of from 0.002 to 0.02 percent by weight of the cumene hydroperoxide feed; (c) conducting the decomposition reaction in the absence of added water so that the reaction mixture does not contain more than about 0.5 percent by weight of water, based on the weight of the reaction mixture; (d) withdrawing reaction mixture from the decomposer at cumene hydroperoxide concentrations not exceeding about 0.5 percent by weight, based on the weight of the reaction mixture; and (e) adding a base to the product withdrawn from the decomposer in excess of amount required to neutralize the decomposition catalyst and sufficient to adjust the pH of the product to from 5 to 9; so that dehydration of dimethyl phenyl carbinol to form alpha-methylstyrene is substantially avoided during the decomposition and distillation steps.

Workup

  1. custominvolves forming a reaction mixture
  2. custompreviously formed
  3. temperaturemaintaining the reaction mixture at elevated temperature
  4. customwithdrawing
  5. customreaction mixture from the decomposer
  6. customremoving the decomposition catalyst from the product
  7. customwithdrawn from the decomposer
  8. distillationfractionally distilling the resulting organic products
  9. customto separately recover an acetone fraction
  10. temperaturemaintaining the reaction mixture in the decomposer at a temperature in the range of from 65° to 105° C.
  11. customthe decomposition reaction in the absence of added water so that the reaction mixture
  12. custom(d) withdrawing
  13. customreaction mixture from the decomposer
  14. concentrationat cumene hydroperoxide concentrations not
  15. additionand (e) adding a base to the product
  16. customwithdrawn from the decomposer in excess of amount

Sources & evidence

ORD record
ord-d3291e863df94a7181056bdacaee8a24
Source dataset
uspto-grants-1977_04
Patent number
US04016213

Reaction notes

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