Pyromellitic Acid → 1,2,4,5-Cyclohexanetetracarboxylic Acid

HRID 1807331Notes

Reaction equation

HRID 1807331 reaction equation
[C:1]([OH:18])(=[O:17])[C:2]1[C:3](=[CH:7][C:8](=[C:12]([CH:16]=1)[C:13]([OH:15])=[O:14])[C:9]([OH:11])=[O:10])[C:4]([OH:6])=[O:5].[H][H]>[Rh].O>[CH:8]1([C:9]([OH:11])=[O:10])[CH2:7][CH:3]([C:4]([OH:6])=[O:5])[CH:2]([C:1]([OH:18])=[O:17])[CH2:16][CH:12]1[C:13]([OH:15])=[O:14]

Participants

5

Reactant 2

HCID 6961Pyromellitic AcidHCID 178418361HCID 178418361, compound3×

Product 1

HCID 28349461,2,4,5-Cyclohexanetetracarboxylic AcidYield 85.1%

Reagents, catalysts & solvents 2

HCID 23948RhodiumCatalystHCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

22.08 kg (86.88 mol) of pyromellitic acid, 8 kg of a catalyst containing rhodium supported on activated carbon (produced by N.E. Chemcat Corporation) and 80 kg of water were charged in a reactor made of Hastelloy (HC22) having a capacity of 200 L, and the interior of the reactor was replaced by nitrogen gas under stirring. The interior of the reactor was then replaced by hydrogen gas, and the temperature was increased to 50° C. under a hydrogen pressure in the reactor of 3.3 MPa. The reaction was performed for 2 hours while maintaining the hydrogen pressure to 3.3 MPa. The hydrogen gas in the reactor was replaced by nitrogen gas, the reaction liquid was taken out from the autoclave, and the reaction liquid was filtered in a hot state to separate the catalyst. The filtrate was concentrated by evaporating water under reduced pressure with a rotary evaporator to deposit crystals. The crystals thus deposited were separated by solid-liquid separation at room temperature and dried to provide 19.24 kg (73.94 mol, yield: 85.1%) of 1,2,4,5-cyclohexanetetracarboxylic acid.

Workup

  1. additionwere charged in a reactor
  2. customthe reaction liquid
  3. customthe reaction liquid
  4. filtrationwas filtered in a hot state
  5. customto separate the catalyst
  6. concentrationThe filtrate was concentrated
  7. customby evaporating water under reduced pressure
  8. customwith a rotary evaporator to deposit crystals
  9. customThe crystals thus deposited were separated by solid-liquid separation at room temperature
  10. customdried

Sources & evidence

ORD record
ord-642635247aa44ef9a28b0aeabfb3d495
Source dataset
uspto-grants-2013_01
Patent number
US08357322B2

Reaction notes

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