摘要 |
<p>Fluoropyridine compounds having a fluoro substituent in at least one of the 2-, 4-, and 6-positions are prepared by treatment of an appropriate 2-, 4-, or 6-chloropyridine compound with excess hydrogen fluoride in a dipolar, aprotic solvent at an elevated temperature and super-atmospheric pressure. Thus, 3,5-dichloro-2,4,6-trifluoropyridine is prepared by heating a mixture of pentachloropyridine, N-methyl-2-pyrrolidinone, and hydrogen fluoride at about 220 DEG C and about 900 kiloPascals of pressure.</p> |