| 摘要 |
<p>Polychloropyridines containing chlorine substituents in the 2, 3, and 6 positions and, optionally, in the 4 and 5 positions, are prepared from polychloro-2,3-lutidines containing at least one chlorine substituent in each methyl group and, optionally, a chlorine substituent in the 6 position by liquid phase chlorination. Lewis acid metal halide catalysts are, optionally, employed. 2,3,5,6-Tetrachloropyridine is, accordingly, prepared by chlorination at 200 to 260 DEG C in the presence of ferric chloride catalyst of a mixture of polychloro-2,3-lutidines obtained by the vapor phase chlorination of 2,3-lutidine.</p> |
