4-Aminophenol → Terephthalic Acid

HRID 2081760Notes

Reaction equation

HRID 2081760 reaction equation
C1([CH2:7][CH2:8][C:9]2[CH:15]=[C:14](O)C=C[C:10]=2[OH:11])C=CC=CC=1.C1C(N)=CC=C([OH:24])C=1.C([O:28][C:29](=[O:31])[CH3:30])(=O)C>>[C:29]([OH:28])(=[O:31])[C:30]1[CH:7]=[CH:8][C:9]([C:10]([OH:11])=[O:24])=[CH:15][CH:14]=1

Participants

4

Reactant 3

HCID 4034-AminophenolHCID 7918Acetic AnhydrideHCID 15365292HCID 15365292, compound

Product 1

HCID 7489Terephthalic Acid

Conditions

Temperature
150 °C

Procedure

17.84 g (83.3 mM) of phenylethylhydroquinone, 1.01 g (9.2 mM) of p-aminophenol and 20 ml of acetic anhydride are fed under a nitrogen stream into a 100 ml flask fitted with a mechanical stirrer, nitrogen inlet tube and distillation head. The temperature is gradually raised to 150° C. This temperature is maintained for 1 hour after which the acetic acid is distilled off for a further hour. The temperature is then lowered to 20° C. over a period of 30 minutes, and after a further 30 minutes is raised to 340° C. over a period of 1 hour distilling off acetic acid. This temperature is maintained for 15 minutes after which the mixture is allowed to cool to ambient temperature. The solid obtained is ground and washed with acetone, hot water and acetone/methanol. After drying under vacuum for 5 hours at 180° C. a polymer is obtained having a melting point of 355° C. and an inherent viscosity of 0.31 dl/g. By heating to 100° C. under high vacuum a polymer is obtained the thermal decomposition of which commences slowly above 400° C. and which shows an inherent viscosity of 4 dl/g.

Workup

  1. customfitted with a mechanical stirrer, nitrogen inlet tube
  2. distillationdistillation head
  3. temperatureThis temperature is maintained for 1 hour after which the acetic acid
  4. distillationis distilled off for a further hour
  5. temperatureafter a further 30 minutes is raised to 340° C. over a period of 1 hour
  6. distillationdistilling off acetic acid
  7. temperatureThis temperature is maintained for 15 minutes after which the mixture
  8. temperatureto cool to ambient temperature
  9. customThe solid obtained
  10. washwashed with acetone, hot water and acetone/methanol
  11. customAfter drying under vacuum for 5 hours at 180° C. a polymer
  12. customis obtained
  13. temperatureBy heating to 100° C. under high vacuum a polymer
  14. customis obtained the thermal decomposition of which commences slowly above 400° C. and which

Sources & evidence

ORD record
ord-8126ab751da2419788da20ec41d474d5
Source dataset
uspto-grants-1993_02
Patent number
US05185424

Reaction notes

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