Isophthalic Acid → Benzene-1,3-dicarboxylic acid--4,4'-(ethane-1,2-diyl)diphenol (1/1)

HRID 866729Notes

Reaction equation

HRID 866729 reaction equation
[C:1]([OH:12])(=[O:11])[C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[CH:3]=1.C(O[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=1[CH2:23][CH2:24][C:25]1[CH:30]=[CH:29]C=[CH:27][C:26]=1OC(=O)C)(=O)C.[C:35](=[O:38])([O-])[O-].[K+].[K+]>>[C:1]([OH:12])(=[O:11])[C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=[O:6])[CH:3]=1.[OH:6][C:21]1[CH:20]=[CH:19][C:18]([CH2:23][CH2:24][C:25]2[CH:30]=[CH:29][C:35]([OH:38])=[CH:27][CH:26]=2)=[CH:17][CH:22]=1

Participants

4

Reactant 3

HCID 8496Isophthalic AcidHCID 11430Potassium CarbonateHCID 2749380Phenol, 2,2′-(1,2-ethanediyl)bis-, diacetate2×

Product 1

HCID 6454818Benzene-1,3-dicarboxylic acid--4,4'-(ethane-1,2-diyl)diphenol (1/1)

Conditions

Temperature
245 °C

Procedure

A charge consisting of 167 parts of isophthalic acid and 298 parts of 1,2-bis(acetoxyphenyl)ethane and 0.005 mols potassium carbonate per mol of 1,2-bis(acetoxyphenyl)ethane is placed in a reaction vessel equipped with a stirrer, condenser and receiver. The vessel is evacuated and purged with nitrogen three times. During the reaction a nitrogen blanket is maintained in the reactor. The temperature is raised to about 245° C. and acetic acid distills. The rate of distillation during the initial 67 percent of reaction is 1.82 ml mol-1 min.-1. The distillation rate tapers after 87 parts of acetic acid have distilled in 55 minutes. The temperature rises slowly to 270° C. during the initial stage. Thereupon the vessel is evacuated to a pressure of about 200 torr for about 5 minutes and the pressure is then slowly reduced to about 1 torr while the temperature is increased to about 290° C. When the amperage on the stirrer motor increases by 0.02 to 0.04 amps, the stirrer motor is switched off and the vacuum is released with nitrogen. A total of 112 parts of acetic acid (98 percent of theoretical) is collected. The rate of evolution of acetic acid during the vacuum stage is 1.67 ml mol-1 min.-1. The prepolymer is extruded from the vessel under slight nitrogen pressure and is reduced in a mill to a powder of particle size in the range of from 0.1 to 0.25 mm. The inherent viscosity of the prepolymer is 0.28. The prepolymer is off white in color.

Workup

  1. customis placed in a reaction vessel
  2. customequipped with a stirrer, condenser
  3. customThe vessel is evacuated
  4. custompurged with nitrogen three times
  5. customDuring the reaction a nitrogen blanket
  6. temperatureis maintained in the reactor
  7. distillationacetic acid distills
  8. distillationThe rate of distillation during the initial
  9. custom67 percent of reaction
  10. distillationThe distillation rate tapers after 87 parts of acetic acid have distilled in 55 minutes
  11. customrises slowly to 270° C.
  12. customThereupon the vessel is evacuated to a pressure of about 200 torr for about 5 minutes
  13. temperatureis increased to about 290° C
  14. temperatureWhen the amperage on the stirrer motor increases by 0.02 to 0.04 amps
  15. customA total of 112 parts of acetic acid (98 percent of theoretical) is collected

Sources & evidence

ORD record
ord-bb587d78da1e479f9e08c4da8d6c4e53
Source dataset
uspto-grants-1978_07
Patent number
US04101517

Reaction notes

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