Process for producing 2- or 4-monosubstituted pyridine and process for selective production and separation of 4-monosubstituted pyridine or a salt thereof

摘要

PROBLEM TO BE SOLVED: To provide an industrial method for producing a 2- or 4- monosubstituted pyridine and a method for separating the 4-monosubstituted pyridine or its salt selectively.;SOLUTION: In the method for producing 2- or 4-monosubstituted pyridine, 1,4- or 1,2-disubstituted dihydropyridine is reacted with a compound selected from a group of (1) manganese dioxide (MnO₂; when (1) is used, the reaction temperature is 70-200C), (2) MnO₂ and trimethylsilylchloride, (3) MnO₂ and hydrochloric acid, (4) bromine and (5) a transition metal salt and hydrogen peroxide. In the method for separating 4-monosubstituted pyridine or its salt selectively, a mixture of 2-monosubstituted pyridine and 4-monosubstituted pyridine obtained by the producing method is reacted with an acid to precipitate the salt of 4-monosubstituted pyridine selectively.;COPYRIGHT: (C)2003,JPO