Back to results
US 2008/0177104 A1Published application
Process for the synthesis of 2,5-dihydroxyterephthalic acid
AssigneeE.I. du Pont de Nemours and Company
InventorJOACHIM C. RITTER
Life of this patent
Estimating the term…
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.
Claims6
1-15. (canceled)
A process for preparing 2,5-dialkoxyterephthalic acid comprising the steps of:
- (a) contacting a 2.5-dihaloterephthalic acid, as described generally by Formula III
- wherein X:=Cl, Br, or I, with base in water to form therefrom the corresponding dibasic salt of the 2,5-dihaloterephthalic acid;
- (b) contacting the dibasic salt of the 2,5-dihaloterephthalic acid with base in water, and with a copper source in the presence of a ligand that coordinates to copper, to form the dibasic salt of 2-5-dihydroxyterephthalic acid from the dibasic salt of 2,5- dihaloterephthalic acid at a solution pH of at least about 8;
- wherein the ligand comprises a Schiff base;
- (c) optionally, separating the dibasic salt of 2,5-dihydroxyterephthalic acid from the reaction mixture in which it is formed;
- (d) contacting the dibasic salt of 2,5-dihydroxyterephthalic acid with acid to form therefrom 2,5-dihydroxyterephthalic acid;
- and
- (e) converting the 2,5-dihydroxyterephthalic acid to a 2,5-dialkoxyterephthalic acid.
5 more elements
A process for preparing a compound, monomer, oligomer or polymer from 2,5-dihydroxyterephthalic acid comprising the steps of:
- (a) contacting a 2,5-dihaloterephthalic acid, as described generally by formula III
- wherein X=Cl, Br, or I, with base in water to form therefrom the corresponding dibasic salt of the 2,5-dihaloterephthalic acid;
- (b) contacting the dibasic salt of the 2,5-dihaloterephthalic acid with base in water and with a copper source in the presence of a ligand that coordinates to copper, to form the dibasic salt of 2,5-dihydroxyterephthalic acid from the dibasic salt of 2,5-dihaloterephthalic acid at a solution pH of at least about 8;
- wherein the ligand comprises a Schiff base;
- (c) optionally, separating the dibasic salt of 2,5-dihydroxyterephthalic acid from the reaction mixture in which it is formed;
- (d) contacting the dibasic salt of 2,5-dihydroxyterephthalic acid with acid to form therefrom 2,5-dihydroxyterephthalic acid;
- and
- (e) subjecting the 2,5-dihydroxyterephthalic acid to a reaction to prepare therefrom a compound, monomer, oligomer or polymer.
5 more elements
Dependencies are inferred from the claim text.