4-Hydroxybenzoic Acid → Phenylparaben

HRID 1657911Notes

Reaction equation

HRID 1657911 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.C(O[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)(=O)C.C(OC1C=CC=CC=1)(=O)C1C=CC=C(C(OC2C=CC=CC=2)=O)C=1>>[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([O:8][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[O:7])=[CH:4][CH:3]=1

Participants

4

Reactant 3

HCID 1354-Hydroxybenzoic AcidHCID 31229Phenyl acetateHCID 69779Diphenyl isophthalate

Product 1

HCID 87250Phenylparaben

Conditions

Temperature
180 °C

Procedure

An aromatic polyester useful as a cross-linking agent for the prepolymer of Example 1 is produced as follows. 414 g. (3 moles) of p-hydroxybenzoic acid, 510 g (3.75 moles) of phenyl acetate and 954 g. (3 moles) of diphenyl isophthalate are charged into a fournecked resin kettle equipped with a thermometer, stirrer, distilling head and a combination nitrogen-HCl inlet tube. The reaction mixture is stirred constantly under a nitrogen atmosphere throughout the run. The reaction mixture is heated to 180°C, and HCl is then bubbled through the mixture for 7 hours, the temperature being held at 180°C. Phenyl p-hydroxybenzoate is thereby produced. The HCl flow is discontinued, the reaction mixture is heated to 200°C at a rate of 10°C/hour, 363 g. (3.3 moles) of hydroquinone is added, and the temperature is further increased to 250°C over a period of 2.5 hours. The distilling head is then heated to 190°C by external heating means to prevent condensation in the distilling head of distillate subsequently to be produced. The reaction mixture is heated to 320°C over a period of 6 hours, held at 320°C for 16 hours, heated to 340°C and held there for 3 hours. During this stage, condensation occurs between the phenyl p-hydroxybenzoate, diphenyl isophthalate and hydroquinone, accompanied by the distillation of phenol. A total of 1127 g. of distillate is collected during the entire run, the distillate containing acetic acid, phenol and the excess phenyl acetate.

Workup

  1. customequipped with a thermometer, stirrer
  2. distillationdistilling head and a combination nitrogen-HCl inlet tube
  3. customHCl is then bubbled through the mixture for 7 hours
  4. custombeing held at 180°C

Sources & evidence

ORD record
ord-24427e0709194716b46474c54427c6f5
Source dataset
uspto-grants-1976_06
Patent number
US03962314

Reaction notes

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