Phenol → Diphenyl carbonate

HRID 333489Notes

Reaction equation

HRID 333489 reaction equation
[OH-:1].[Na+].C(Cl)Cl.[C:6](Cl)(Cl)=[O:7].[C:10]1([OH:16])[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>O>[C:6](=[O:7])([O:1][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)[O:16][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

6

Reactant 4

HCID 996PhenolHCID 6344DichloromethaneHCID 6371PhosgeneHCID 14798Sodium Hydroxide4×

Product 1

HCID 7597Diphenyl carbonate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
33 °C

Procedure

In a vertical, cooled tube reactor, a mixture of 145.2 kg/h of 14.5% strength sodium hydroxide solution, produced by diluting 65.8 kg/h of a 32.0% strength sodium hydroxide solution with 79.4 kg/h of deionized water (DI water), and 48.3 kg/h of phenol was continuously combined with a solution of 86.2 kg/h of methylene chloride and 27.5 kg/h of phosgene (8 mol % excess based on phenol). This reaction mixture was cooled to a temperature of 33° C. and after an average residence time of 15 seconds, a pH of 11.5 was measured. In the second stage of the process, 5.4 kg/h of 50.0% strength NaOH were then metered into this reaction mixture so that the pH of the second reaction stage after a further residence time of 5 minutes is 8.5. In the second stage of the process, the reaction mixture was mixed continually by passage through a tube provided with constrictions, The reaction temperature was, after renewed addition of the NaOH, set to 30° C. by cooling. After the organic phase had been separated off from the aqueous phase (reaction wastewater), the DPC solution was washed with 0.6% strength hydrochloric acid and water. Removal of the solvent gave 99.9% strength diphenyl carbonate. The reaction wastewater was not combined with the washing phases and was freed of solvent residues and catalysts by stripping with steam. After neutralization (pH 7) with hydrochloric acid and treatment with activated carbon, the reaction wastewater contained 17.0% of NaCl and <2 ppm of phenol.

Workup

  1. temperatureIn a vertical, cooled tube reactor
  2. customproduced
  3. customafter an average residence time of 15 seconds
  4. additionIn the second stage of the process, the reaction mixture was mixed continually by passage through a tube
  5. customprovided with constrictions
  6. customset to 30° C.
  7. temperatureby cooling
  8. customAfter the organic phase had been separated off from the aqueous phase (reaction wastewater)
  9. washthe DPC solution was washed with 0.6% strength hydrochloric acid and water
  10. customRemoval of the solvent

Sources & evidence

ORD record
ord-e05aef364d93416d8a6deabc65062ecd
Source dataset
uspto-grants-2014_11
Patent number
US08882984B2

Reaction notes

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