Phthalic Anhydride → Benzoic acid, 2,2'-(dioxydicarbonyl)bis-

HRID 2082964Notes

Reaction equation

HRID 2082964 reaction equation
[C:1]1(=[O:11])[O:6][C:4](=[O:5])[C:3]2=[CH:7][CH:8]=[CH:9][CH:10]=[C:2]12.[OH-:12].[Na+]>OO>[CH:9]1[CH:10]=[C:2]([C:1]([OH:6])=[O:11])[C:3]([C:4]([O:12][O:12][C:4]([C:3]2[C:2]([C:1]([OH:6])=[O:11])=[CH:10][CH:9]=[CH:8][CH:7]=2)=[O:5])=[O:5])=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 6811Phthalic Anhydride2×HCID 14798Sodium Hydroxide

Product 1

HCID 169852Benzoic acid, 2,2'-(dioxydicarbonyl)bis-

Reagents, catalysts & solvents 1

HCID 784Hydrogen PeroxideSolvent

Procedure

Diphthaloyl peroxide was prepared by adding finely powdered phthalic anhydride (7.2g) gradually over a period of five minutes to a solution of hydrogen peroxide (0.46% by weight, 90 cm3) maintained at a temperature of between 1° to 3° C by the use of a cooling jacket, and the pH of 9 plus or minus 0.2 by dropwise addition of sodium hydroxide sufficient to counteract the generation of acidity as the reaction proceeded. The solution was stirred constantly, so that the proportion of the finely powdered phthalic anhydride which did not go into solution, remained in suspension, and the temperature and pH were controlled for a further 25 minutes, by which time substantially all the hydrogen peroxide had been consumed. The suspension was filtered into sulphuric acid (10% by weight, 30 cm3) and substantially all the diphthaloyl peroxide precipitated out. The solid which had been filtered off was washed with water and then dried to recover phthalic anhydride (3.03g). The acidified filtrate was centrifuged and the precipitate, separated thereby, was washed with water (40 cm3) and dried giving diphthaloyl peroxide (3.l g). An iodometric assay of the crude product showed that it contained 89.1% of active material, and negligible amount of monoperoxyphthalic acid, giving a reaction yield of 59.4%, based on consumption of phthalic anhydride.

Workup

  1. customDiphthaloyl peroxide was prepared
  2. temperaturemaintained at a temperature of between 1° to 3° C by the use of a cooling jacket
  3. customthe hydrogen peroxide had been consumed
  4. filtrationThe suspension was filtered into sulphuric acid (10% by weight, 30 cm3)
  5. customsubstantially all the diphthaloyl peroxide precipitated out
  6. filtrationThe solid which had been filtered off
  7. washwas washed with water
  8. customdried
  9. customto recover phthalic anhydride (3.03g)
  10. customthe precipitate, separated
  11. washwas washed with water (40 cm3)
  12. customdried

Sources & evidence

ORD record
ord-b9a2eac7558d405781527d5602476674
Source dataset
uspto-grants-1978_04
Patent number
US04083877

Reaction notes

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