| 摘要 |
Process for the production of 2-halopyridine derivatives having the formula: <IMAGE> wherein X is halogen, R is -COOH or a lower alkyl radical and n is a number between 0 and 4. The corresponding 2-pyridine carboxylic acid-N-oxide derivatives having the formula: <IMAGE> are reacted in the presence of an excess of organic anhydrides, tertiary alkylamines and a halogen-producing compound having the formula CHtXm, wherein t is 1 or 2, m is 2 or 3 and X is halogen, or having the formula C2HpXm, wherein p is 3 or 4, m is 2 or 3 and X is halogen. The reaction mixture is adjusted to a pH value of 12 to 13 and the desired product is isolated from the mixture. Compound comprising (i) a 2-pyridine carboxylic acid-N-oxide derivative, (ii) an organic anhydride, (iii) a tertiary amine and (iv) a halogen-producing compound having the formula CHnXm. The composition can be used as the starting ingredients for the above process.
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