Terephthalic Acid → Phthalide

HRID 891230Notes

Reaction equation

HRID 891230 reaction equation
C(O)(=O)[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.O1CC[CH2:16]OO1>OS(O)(=O)=O.O=S(=O)=O>[C:6]1([C:5]2[C:9](=[CH:10][CH:2]=[CH:3][CH:4]=2)[CH2:16][O:8]1)=[O:7]

Participants

4

Reactant 2

HCID 7489Terephthalic AcidHCID 19593658CID 19593658

Product 1

HCID 6885Phthalide

Reagents, catalysts & solvents 1

HCID 24681Fuming sulfuric acidSolvent

Conditions

Temperature
145 °C

Procedure

Terephthalic acid was suspended in 25-30% oleum. Trioxane was added and the mixture was heated to 140-150° C. for 4-8 hours. The reaction mixture was cooled and then quenched by cautious addition of water at less than 80° C. The resulting suspension was cooled to about 40° C. and the solid was filtered off. The filter cake was washed with water followed by propan-2-ol before slurrying the solid in propan-2-ol at reflux for 30 minutes. After cooling to 20-25° C. the product was filtered off, washed with propan-2-ol and dried at 60-70° C. under reduced pressure.

Workup

  1. temperatureThe reaction mixture was cooled
  2. customquenched by cautious addition of water at less than 80° C
  3. temperatureThe resulting suspension was cooled to about 40° C.
  4. filtrationthe solid was filtered off
  5. washThe filter cake was washed with water
  6. temperatureat reflux for 30 minutes
  7. temperatureAfter cooling to 20-25° C. the product
  8. filtrationwas filtered off
  9. washwashed with propan-2-ol
  10. customdried at 60-70° C. under reduced pressure

Sources & evidence

ORD record
ord-543a51228027465599b2934133cb5483
Source dataset
uspto-grants-2006_02
Patent number
US07002025B2

Reaction notes

Loading…