Process for the synthesis of 2,5-dihydroxyterephthalic acid

A technology of hydroxyterephthalic acid and dialkoxy terephthalic acid, which is applied in the field of synthesizing 2,5-dihydroxyterephthalic acid, which can solve the problems of decreased productivity, long reaction time, conversion rate, etc.

Inactive Publication Date: 2009-09-23
EI DU PONT DE NEMOURS & CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The various prior art processes for the preparation of hydroxybenzoic acids are characterized by long reaction times and limited conversions, leading to a significant drop in productivity, or need to be carried out under pressure and / or at elevated temperatures (typically 140 to 250°C) for reasonable rates and productivity

Method used

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  • Process for the synthesis of 2,5-dihydroxyterephthalic acid
  • Process for the synthesis of 2,5-dihydroxyterephthalic acid
  • Process for the synthesis of 2,5-dihydroxyterephthalic acid

Examples

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Embodiment

[0055] The invention is further defined in the following examples. These examples, while indicating preferred embodiments of the invention, are given by way of illustration only and do not limit the scope of the appended claims. From the above discussion and these Examples, the essential characteristics of this invention can be clearly understood, and without departing from the spirit and scope of the invention, it can be modified to adapt it to various usages and conditions.

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Abstract

2,5-dihydroxyterephthalic acid is produced in high yields and high purity from 2,5-dihaloterephthalic acid by contact with a copper source and a ligand that coordinates to copper under basic conditions.

Description

technical field [0001] The present invention relates to the preparation of hydroxybenzoates which are valuable for a variety of uses, for example as intermediates or as monomers for the preparation of polymers. Background technique [0002] Hydroxybenzoic acid compounds can be used as intermediates to make many valuable materials, including pharmaceuticals and compounds with crop protection effects, and as monomers to make polymers. In particular, 2,5-dihydroxyterephthalic acid (Formula I, "DHTA") is a synthetic high-strength fiber made, for example, of poly[(1,4-dihydrodiimidazo[4,5-b:4 ', 5'-e]pyridine-2,6-diyl)(2,5-dihydroxy-1,4-phenylene)] useful monomers for fibers. [0003] [0004] Various methods for the preparation of 2,5-dihydroxyterephthalic acid and other hydroxybenzoates are known. Marzin in "Journal fuer Praktische Chemie", 1933, 13, 103-106 proposed the synthesis of 2,5-dibromoterephthalic acid (formula II, "DBTA") in the presence of copper powder - Dihy...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C07C51/367C07C51/41C07C51/02C07C65/05
CPCC07C51/412C07C51/367C07C51/02C07C65/05
InventorJ·C·里特
OwnerEI DU PONT DE NEMOURS & CO