Process for the preparation of p-toluic acid by liquid phase oxidation of p-xylene in water
US7598415B2 · kind B2 · utility
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6References
19Claims
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Key dates
| Filing date | Mar 17, 2006 |
| Grant date | Oct 6, 2009 |
| Priority date | — |
| Expiry date | Mar 17, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/584
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a process for the preparation of p-toluic acid by liquid phase oxidation of p-xylene using oxygen or air as oxidant in the presence of p-toluic acid, water as solvent and cobalt salt or its combinations with salts of Ce, Mn as catalyst. Oxidation is carried out at 130-190° C. and pressure sufficient to keep water in liquid state. Oxidation step is followed by filteration to obtain p-toluic acid as major product. Untreated p-xylene is recovered and recycled and the catalyst is recovered from aqueous phase and is recycled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.