4,5-Dichlorophthalic acid → 4,5-Dichlorophthalic anhydride

HRID 1648535Notes

Reaction equation

HRID 1648535 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([C:12]([OH:14])=[O:13])[C:5](=[CH:9][C:10]=1[Cl:11])[C:6]([OH:8])=O>C(OC(=O)C)(=O)C>[Cl:11][C:10]1[CH:9]=[C:5]2[C:6](=[O:8])[O:14][C:12](=[O:13])[C:4]2=[CH:3][C:2]=1[Cl:1]

Participants

3

Reactant 1

HCID 926004,5-Dichlorophthalic acid

Product 1

HCID 703344,5-Dichlorophthalic anhydrideYield 92%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

200 g of 4,5-dichlorophthalic acid (851 mmol, M.W. 235) was suspended in 480 ml of acetic anhydride and the solution was heated to reflux for 5 hours. The solution was allowed to cool to room temperature over 2 hours, then cooled to 0° C. and filtered and washed with 100 ml of hexane and dried to provide the title compound with a 92% yield (170 g). M.P. 184° C.-186° C. 1H NMR(CDCI3) : 8.1 (s).

Workup

  1. temperaturethe solution was heated
  2. temperatureto reflux for 5 hours
  3. temperaturecooled to 0° C.
  4. filtrationfiltered
  5. washwashed with 100 ml of hexane
  6. customdried

Sources & evidence

ORD record
ord-b5e7c02bb3774cde844638c12059c28a
Source dataset
uspto-grants-1995_07
Patent number
US05436368

Reaction notes

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