Sulfuric Acid → 3-Ethylphenol

HRID 1632339Notes

Reaction equation

HRID 1632339 reaction equation
S(=O)(=O)(O)O.S([O-])([O-])(=O)=[O:7].[Na+].[Na+].[CH2:13]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[CH3:14]>>[CH2:13]([C:15]1[CH:20]=[C:19]([OH:7])[CH:18]=[CH:17][CH:16]=1)[CH3:14]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 7500EthylbenzeneHCID 24436Sodium Sulfate

Product 1

HCID 121013-EthylphenolYield 396.7%

Conditions

Temperature
170 °C

Procedure

A four-necked flask (2 liters-volume) was charged with 98% sulfuric acid (1200 g). Anhydrous sodium sulfate (102 g, 6 mol %) and then ethylbenzene (424 g) were added thereto in 30 minutes while stirring. Temperature was gradually elevated to 200° C. over 2 hours while evaporated water was withdrawn. The heating was continued with stirring for 4 hours at the same temperature in order to isomerize. Then, the mixture was cooled to 170° C. Water (2000 g) was dropped at a uniform rate into the stirred mixture at the same temperature over 10 hours in order to hydrolyze. The obtained reaction mass was left to stand at 150° C. for 30 minutes to form layers. The layer of sulfuric acid (854 g) was removed. The layer of sulfonic acid (1074 g) was neutralized to pH 7.8 with 50% potassium hydroxide and added dropwise to a mixture of sodium hydroxide (563 g) and potassium hydroxide (83 g) mutually melting at 330° C. in a 2 liter reaction vessel. The mixture was heated to 340° C. and maintained with stirring at this temperature for 1 hour. Then, the mixture was dissolved in water (2000 ml) and neutralized to pH 7.2 with 35% hydrochloric acid. The produced phenols were extracted with ether and distilled to give crude m-ethylphenol (348 g, 71% yield based on consumed ethylbenzene), which showed a purity of 98.2% after fractional distillation.

Workup

  1. waitTemperature was gradually elevated to 200° C. over 2 hours
  2. customwhile evaporated water
  3. customwas withdrawn
  4. stirringwith stirring for 4 hours at the same temperature in order
  5. additionWater (2000 g) was dropped at a uniform rate into the stirred mixture at the same temperature over 10 hours in order
  6. customThe obtained reaction mass
  7. waitwas left
  8. waitto stand at 150° C. for 30 minutes
  9. customto form layers
  10. customThe layer of sulfuric acid (854 g) was removed
  11. additionadded dropwise to a mixture of sodium hydroxide (563 g) and potassium hydroxide (83 g) mutually melting at 330° C. in a 2 liter reaction vessel
  12. temperatureThe mixture was heated to 340° C.
  13. temperaturemaintained
  14. stirringwith stirring at this temperature for 1 hour
  15. dissolutionThen, the mixture was dissolved in water (2000 ml)
  16. extractionThe produced phenols were extracted with ether
  17. distillationdistilled

Sources & evidence

ORD record
ord-474bc03df1d446d8b0804efd6428c1c5
Source dataset
uspto-grants-1984_10
Patent number
US04475002

Reaction notes

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