4,5-Dichlorotetrahydrophthalic anhydride → 4,5-Dichlorophthalic anhydride

HRID 345956Notes

Reaction equation

HRID 345956 reaction equation
[Cl:1][CH:2]1[C:12]([Cl:13])=[CH:11][CH:5]2[C:6]([O:8][C:9](=[O:10])[CH:4]2[CH2:3]1)=[O:7]>ClC1C=CC(Cl)=CC=1Cl>[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[O:10])[O:8][C:6](=[O:7])[C:5]2=[CH:11][C:12]=1[Cl:13]

Participants

3

Reactant 1

HCID 541398954,5-Dichlorotetrahydrophthalic anhydride

Product 1

HCID 703344,5-Dichlorophthalic anhydrideYield 80%

Reagents, catalysts & solvents 1

HCID 131,2,4-TrichlorobenzeneSolvent

Conditions

Temperature
190 °C

Procedure

A mixture of 5.0 grams (22.7 mmol) of 4,5,-dichlorotetrahydrophthalic anhydride and of activated carbon (Darco KB-60, 1.0 gram) was slurried with 10 mL of 1,2,4-trichlorobenzene and heated to 190° C. for 25 h. The reaction mixture was then filtered while hot and the filtrate was allowed to cool to room temperature, at which time the product precipitated out of solution. After the addition of 5 mL of hexanes to ensure complete precipitation, the product was collected and washed with hexanes. Drying in a vacuum dessicator (60° C., 0.25 mm Hg, 24 h) gave 1 (3.9 g, 80% yield, 99.6% purity by GC), mp 185°-16.5° C. (lit mp 187° C.).

Workup

  1. filtrationThe reaction mixture was then filtered while hot and the filtrate
  2. temperatureto cool to room temperature, at which time the product
  3. customprecipitated out of solution
  4. additionAfter the addition of 5 mL of hexanes
  5. customprecipitation
  6. customthe product was collected
  7. washwashed with hexanes
  8. customDrying in a vacuum dessicator (60° C., 0.25 mm Hg, 24 h)
  9. customgave 1 (3.9 g, 80% yield, 99.6% purity by GC), mp 185°-16.5° C. (lit mp 187° C.)

Sources & evidence

ORD record
ord-87fc976f0eb64d12bb11b8ccf192dc43
Source dataset
uspto-grants-1991_10
Patent number
US05059697

Reaction notes

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