| 摘要 |
PURPOSE:To prepare selectively a 2-hydroxyhalogenopyridine useful as a raw material for agricultural chemicals, etc., by hydrolyzing a halogenopyridine with an alkali aqueous solution using a phase transfer catalyst such as a quaternary ammonium salt, quaternary phosphonium salt, etc. as a catalyst. CONSTITUTION:A halogenopyridine (e.g., 2,3-dichloropyridine, etc.) shown by the formulaI(X is halogen; n is 2-4) is hydrolyzed with an alkali aqueous solution (e.g., >=50wt% NaOH aqueous solution, etc.), to give a 2-hydroxyhalogenopyridine shown by the formula II. In the reaction, a phase transfer catalyst such as benzyltriethylammonium chloride, tetraphenylphosphonium chloride, 18- crown-6, etc. or a nitrogen-containing heterocylic compound such as pyridine, etc. is used as a catalyst. |
