| 摘要 |
This invention relates to a two stage process for preparing 2,6-pyridinedicarboxylic acid or dipicolinic acid from 2,6-dimethyl-pyridine through oxidation of the latter in an acid environment with hexavalent chromium salts and formation of a molar addition compound between dicarboxylic acid, being formed by oxidation, and chromic anhydride in the first stage, and subsequent hot hydrolysis of the addition product so obtained, thus isolating 2,6-pyridinedicarboxylic acid therefrom in the second stage. The invention also comprises the above mentioned intermediate complex addition compound and the 2,6-pyridinedicarboxylic acid of high purity, obtained by the process according to said invention.
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