Patent · US Expired

Process for producing cis-4,5-dihydro-4,5-dihydroxyphthalic acid

US5037748A · kind A · utility

1Cited by
0References
17Claims
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Assignee

Inventors

Key dates

Filing dateJul 30, 1990
Grant dateAug 6, 1991
Priority date
Expiry dateJul 30, 2010

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S435/874
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

A process for producing cis-4,5-dihydro-4,5-dihydroxyphthalic acid which comprises producing cis-4,5-dihydro-4,5-dihydroxyphthalic acid and/or a salt thereof from phthalic acid and/or a salt thereof using a microorganism whose activity to decompose cis-4,5-dihydro-4,5-dihydroxyphthalic acid and/or a salt thereof has disappeared or diminished, acidifying the product system unless it is acidic, and then extracting therefrom cis-4,5-dihydro-4,5-dihydroxyphthalic acid with such an organic solvent that it is miscible with water in any proportion and the mixture of the organic solvent with water can be separated into two layers upon adding a salt thereto, in the presence of a salt, or with an alcohol having 4 carbon atoms. The process enables one to produce cis-4,5-dihydro-4,5-dihydroxyphthalic acid from phthalic acid and/or its salt in a high yield.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.