Acetic Acid → Terephthalic Acid

HRID 1641595Notes

Reaction equation

HRID 1641595 reaction equation
ON1[C:6](=O)[CH2:5][CH2:4][C:3]1=[O:8].CC1C=C[C:13]([CH3:16])=CC=1.[O:17]=O.[C:19]([OH:22])(=[O:21])[CH3:20]>>[C:19]([OH:22])(=[O:21])[C:20]1[CH:16]=[CH:13][C:4]([C:3]([OH:8])=[O:17])=[CH:5][CH:6]=1

Participants

5

Reactant 4

HCID 176Acetic AcidHCID 977OxygenHCID 7809P-XyleneHCID 80170N-Hydroxysuccinimide

Product 1

HCID 7489Terephthalic AcidYield 98%

Conditions

Temperature
100 °C

Procedure

In this example, a solution of 0.1158 g (1.01 mmol) of N-hydroxysuccinimide, 0.5199 g (4.9 mmol) of p-xylene and 0.1273 g (0.511 mmol) CAT in 40 ml of acetic acid was heated to 100° C. in a Parr Hastelloy reactor fitted with temperature and pressure controllers. After the temperature reached 100° C., 860 psi of air was slowly introduced into the reactor. The mixture was stirred under pressure for one hour at 100° C., the pressure was released, and the mixture cooled to room temperature. Within roughly 15 minutes following O2 introduction, a rapid temperature rise occurred (due to heat generated by the exothermic oxidation) accompanied by a drop in reactor pressure (due to consumption of O2 in the liquid phase reaction) indicating rapid reaction. These profiles are steep and level off within minutes after induction (typical T and P profiles will be provided in the patent application). The white solid of terephthalic acid (TPA) was filtered, and the filtrate analyzed by HPLC using biphenyl as the internal standard. The solid TPA product was washed with additional acetic acid (20 ml) and dried in an oven at 120° C. for six hours to obtain 0.795 g of TPA (yield: 98% based on the initial moles of p-xylene reacted). Analysis: 97.7% TPA, 2.0% carboxybenzaldehyde (CBA), and 0.3% p-toluic acid (PTA).

Workup

  1. customfitted with temperature and pressure controllers
  2. customreached 100° C.
  3. addition860 psi of air was slowly introduced into the reactor
  4. temperaturethe mixture cooled to room temperature
  5. waitWithin roughly 15 minutes following
  6. temperatureto heat
  7. customaccompanied by a drop in reactor
  8. custompressure (due to consumption of O2
  9. customin the liquid phase reaction)
  10. customreaction
  11. customlevel off within minutes after induction (typical T and P profiles will be provided in the patent application)
  12. filtrationThe white solid of terephthalic acid (TPA) was filtered
  13. washThe solid TPA product was washed with additional acetic acid (20 ml)
  14. customdried in an oven at 120° C. for six hours

Sources & evidence

ORD record
ord-24850c59e9ad4345a126173bb8df4f3c
Source dataset
uspto-grants-2012_02
Patent number
US08115029B2

Reaction notes

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