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

HRID 1443023

Reaction equation

HRID 1443023 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]>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

4

Reactant 2

HCID 6961Pyromellitic AcidHCID 178418361HCID 178418361, compound4×

Product 1

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

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

A 5-L autoclave made of Hastelloy (HC22) was charged with 552 g of pyromellitic acid, 200 g of a catalyst formed by supporting Rh on activated carbon (available from N.E. Chemcat Corporation) and 1656 g of water. The interior of the autoclave was replaced with a hydrogen gas while stirring the contents. Then, the hydrogen pressure was adjusted to 5.0 MPa and the temperature was raised to 60° C. While maintaining the hydrogen pressure at 5.0 MPa, the reaction was allowed to proceed for 2 h. After replacing the hydrogen gas in the autoclave with nitrogen gas, the reaction product solution was discharged from the autoclave. The reaction product solution was filtered while it was hot to separate the catalyst. The filtrate was concentrated by distillation under reduced pressure using a rotary evaporator to evaporate off water, thereby precipitating crystals. The precipitated crystals were collected by a solid-liquid separation at room temperature, and then, dried to obtain 481 g of 1,2,4,5-cyclohexanetetracarboxylic acid (yield: 85.0%).

Workup

  1. customformed
  2. filtrationThe reaction product solution was filtered while it
  3. customto separate the catalyst
  4. concentrationThe filtrate was concentrated by distillation under reduced pressure
  5. customa rotary evaporator
  6. customto evaporate off water
  7. customprecipitating crystals
  8. customThe precipitated crystals were collected by a solid-liquid separation at room temperature
  9. customdried

Sources & evidence

ORD record
ord-ad466644a87a442ab26ac0104f593a99
Source dataset
uspto-grants-2010_02
Patent number
US07659360B2

Linked notes

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