| 摘要 |
<p>Chloropyridines of the formula wherein either R is chlorine and R' is methyl or trifluoromethyl, o R is methyl, trichloromethyl or trifluoromethyl and R' is chlorine, or R and R' are methyl, can be ootained by a novel, simple process oy the addition of trichloroacetaldehyde to methacrylonitrile or .alpha.-trifluoromethacrylonitrile, 2,2-dichloropropionaldehyde, pentachloropropionaldehyde or 2,2-dichloro-3,3,3-trifluoropropionaldehyde to acrylonitrile, or 2,2-dichloropropionaledehyde to methacrylonitrile, in the presence of a catalyst, in particular copper powder or copper(I) chloride, and cyclising the open-chain intermediate obtained. The chloropyridines of the formula (I) are known per se and are suitable for the production of different compounds, in particular of insecticides and herbicides.</p> |
