摘要 |
<p>Chloromethylpyridine hydrochlorides such as 3-chloromethylpyridine hydrochloride, an important pharmaceutical intermediate, are prepared in high yield and high purity by reacting the corresponding pyridyl carbinol with a slight excess of thionyl chloride, in solution in an inert solvent such as toluene. The pyridyl carbinol solution is added to the thionyl chloride gradually and under its surface, to prevent the formation of impurities. The product is recovered by applying vacuum or nitrogen purge to the reaction mixture to assist precipitation, followed by filtration and washing.</p> |