Benzoic Acid → Benzoic anhydride

HRID 1388086Notes

Reaction equation

HRID 1388086 reaction equation
[C:1]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:17]([OH:25])(=[O:24])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C1(C2C=CC=CC=2C(O)=O)C=CC=CC=1.ClCl.C1(C(Cl)(Cl)[Cl:50])C=CC=CC=1>[Hg]>[C:1]([O:9][C:10](=[O:24])[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)(=[O:8])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1.[C:17]([Cl:50])(=[O:25])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

8

Reactant 5

HCID 243Benzoic Acid2×HCID 2345Benzyl BenzoateHCID 7367BenzotrichlorideHCID 24526ChlorineHCID 70357o-Phenylbenzoic acid

Product 2

HCID 7167Benzoic anhydrideHCID 7412Benzoyl chloride

Reagents, catalysts & solvents 1

HCID 23931MercuryCatalyst

Procedure

1,000 g of a distillate prepared as described above (74.2% of benzyl benzoate, 13.4% of benzoic acid and 10.0% of phenylbenzoic acid) are chlorinated at 160° C. under irradiation with UV light (mercury vapour lamp). After 5 hours, the mixture has increased in weight by approx. 260 g by absorption of chlorine. 330 g of benzotrichloride and 1,1 g of FeCl3 are added dropwise to the mixture at 150° C. to convert benzoic acid which is still present and benzoic acid anhydride which has been formed into benzoyl chloride. After the evolution of hydrogen chloride has ended, the mixture is fractionally distilled in vacuo. 1,265 g of pure benzoyl chloride (yield greater than 92%, relative to benzoic acid, benzyl benzoate, phenylbenzoic acid and benzotrichloride added) are obtained in this distillation. 250 g remain in the distillation residue.

Workup

  1. custom1,000 g of a distillate prepared

Sources & evidence

ORD record
ord-53a8ba48a65b448db3fd34f8ad068932
Source dataset
uspto-grants-1984_02
Patent number
US04430181

Reaction notes

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