Terephthalic Acid → 4-Formylbenzoic acid
Reaction equation
[C:1](O)(=[O:11])[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1>O>[C:6]([C:5]1[CH:9]=[CH:10][C:2]([CH:1]=[O:11])=[CH:3][CH:4]=1)([OH:8])=[O:7]Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 1
Procedure
A process for the production of high purity terephthalic acid comprising the steps of dissolving a crude terephthalic acid in a solvent consisting essentially of water to form an aqueous solution of crude terephthalic acid having a content of 4-carboxybenzaldehyde of at least 1,000 ppm, said crude terephthalic acid being obtained by the oxidation of a paradialkylbenzene, subjecting said aqueous solution of crude terephthalic acid having a content of 4-carboxybenzaldehyde of at least 1,000 ppm to oxidation at a temperature of from 230° to 300° C. and a pressure of 30-100 Kg/cm2 by an oxygen-containing gas at a feed rate of 0.4-10 moles of oxygen per mole of 4-carboxybenzaldehyde contained in the crude terephthalic acid, said oxidation being conducted in the presence of a fixed bed catalyst, to obtain a resultant solution, said aqueous solution of crude terephthalic acid having a concentration of 100-700 g of terephthalic acid per liter of aqueous solution, and subjecting the resultant solution to hydrogenation by hydrogen at a temperature in the range of 270°-300° C. and a hydrogen partial pressure of 5-15 Kg/cm2 in the presence of a catalyst to obtain a high purity terephthalic acid.
Sources & evidence
- ORD record
- ord-2b0c01d0c73645699d6720587b0773dc
- Source dataset
- uspto-grants-1992_11
- Patent number
- US05166420
Reaction notes
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