Process for preparation of 2,3-pyridine dicarboxylic acid


Application Number: 00108288
Application Date: 2000.05.10
Publication Number: 1274720
Publication Date: 2000.11.29
Priority Information: 1999/5/10 AT A 832/99
International: C07D213/78
Applicant(s) Name: DSM Fine Chemical Austria GmbH
Address:
Inventor(s) Name: K-H. Gieslbrecket;E. Biendorfill;K. Reth
Patent Agency Code: 11038
Patent Agent: huang zexiong
Abstract Process for the preparation of pure 2,3-pyridinedicarboxylic acids of the formula I which are substituted in position 4 and/or 5 and/or 6 by R1, where R1 is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxy-C1-C4 alkyl, halogen, hydroxyl or nitro, from quinolines of the formula II in which R1 is as defined above, and which are substituted in position 6 and/or 7 by R2, where R2 is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxy-C1-C4 alkyl, halogen, hydroxyl, nitro or amino, which are reacted in the first step in aqueous sulfuric acid or nitric acid solution with ozone in the ratio of from 1:2 to 1:3 at temperatures from 0 to +50 DEG C., and the resulting peroxide solution is then reacted at temperatures of from +0 to +100 DEG C. in the presence of 0.5-4.0 mol of oxidizing agent per mole of ozonolysis product formed, after which the pH of the reaction solution is adjusted to 0.2 to 3, the mixture is cooled to 0 to 30 DEG C., and the precipitated pyridinedicarboxylic acid is isolated.