| 摘要 |
Production of 2,3,5-trichloropyridine by reacting 3,5-dichloro-2-pyridone at 30 DEG to 150 DEG with phosgene in the presence of an N,N-disubstituted formamide of the formula <IMAGE> in which R1 and R2 can be identical or different and are each an alkyl group having 1 to 4 carbon atoms, or R1 and R2 together with the nitrogen atom form the pyrrolidino, piperidino or morpholino, and in the presence of an inert solvent. 2,3,5-Trichloropyridine is a valuable intermediate for producing herbicidally active alpha -[4-(3',5'-dichloropyrid-2-yloxy)-phenoxy]-alkanecarboxylic acids and derivatives thereof.
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