| 摘要 |
The new process for preparing ethyl 3-(2,5,6-trihalopyridin-3-yl)-3-oxopropionate from 2,5,6-trihalo-3-cyanopyridine in accordance with the present invention comprises reacting 2,5,6-trihalo-3-cyanopyridine with ethyl haloacetate at the presence of a transition metal in powder in anhydrous solvent, and treating the resulting solution with HCl. In particular, the new process for preparing ETPO from THCP comprises heating 2,5,6-trihalo-3-cyanopyridine and a transition metal in powder in anhydrous solvent to the boiling point, reacting 2,5,6-trihalo-3-cyanopyridine with ethyl haloacetate by adding ethyl haloacetate dropwise to the resulting solution, cooling the resulting solution to about 10° C., adding concentrated HCl and distilled water to the resulting solution during agitation thereof, and filtering the product.
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