Formaldehyde → 1,3-Dihydro-1-oxoisobenzofuran-5-carboxylic acid

HRID 2180315Notes

Reaction equation

HRID 2180315 reaction equation
[C:1]([OH:12])(=[O:11])[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.OS(O)(=O)=O.O=S(=O)=O.[CH2:22]=O>>[C:6]([C:5]1[CH:9]=[C:10]2[C:2](=[CH:3][CH:4]=1)[C:1](=[O:12])[O:11][CH2:22]2)([OH:8])=[O:7]

Participants

4

Reactant 3

HCID 712FormaldehydeHCID 7489Terephthalic AcidHCID 24681Fuming sulfuric acid

Product 1

HCID 785171,3-Dihydro-1-oxoisobenzofuran-5-carboxylic acidYield 83%

Conditions

Temperature
125 °C

Procedure

Terephthalic acid (10 kg) is charged into a reactor. Oleum (20% (18-24% SO3); 6 kg/kg terephthalic acid ) is added and then paraformaldehyde (1.33 equivalents, 0.24 kg/kg terephthalic acid) is added. The mixture is agitated at 125° C. for 17 hours. Water (13 kg/kg terephthalic acid and filter aid is added, the temperature is adjusted to about 70° C. The precipitate is filtered of, washed with water and suspended in water. The pH of the suspension is adjusted to about 7 with NaOH, activated carbon, 0.07 kg/kg terephthalic acid is added, and then the mixture is filtered, the precipitate is rinsed with water. The temperature of the filtrate is adjusted to about 65° C. and the pH is adjusted to about 2 with 50% sulfuric acid. The 5-carboxyphthalide precipitated is separated by filtration washed and dried. Yield 83%.

Workup

  1. filtrationWater (13 kg/kg terephthalic acid and filter aid
  2. additionis added
  3. customis adjusted to about 70° C
  4. filtrationThe precipitate is filtered of,
  5. washwashed with water
  6. additionis added
  7. filtrationthe mixture is filtered
  8. washthe precipitate is rinsed with water
  9. customis adjusted to about 65° C.
  10. customThe 5-carboxyphthalide precipitated
  11. customis separated by filtration
  12. washwashed
  13. customdried

Sources & evidence

ORD record
ord-a6a913cf410a40d2b9657bc43ad1f452
Source dataset
uspto-grants-2005_05
Patent number
US06888009B2

Reaction notes

Loading…