| 摘要 |
PURPOSE:To obtain the titled compound useful as a plant growth inhibitor, safely in high yield without necessitating expensive apparatus and distillation process, etc., with simple extraction and decoloration process, etc., by subjecting naphthalene, etc., to chloromethylation and carbonylation followed by concentration, extraction, hydrolysis, etc. CONSTITUTION:According to the process shown in the reaction formula, naphthalene is made to react with formaldehyde and hydrochloric acid in the presence of an acid catalyst to obtain a solution containing alpha-chloromethylnaphthalene. The solution is made to react with carbon monoxide, a basic substance and an alcohol in the presence of cobalt carbonyl catalyst while continuously adding the catalyst, etc., to the reaction system without separating the solution from the system. The catalyst in the produced solution of a naphthylacetic acid ester is decomposed by the treatment with an acid and oxygen and excessive alcohol is distilled out. The resultant concentrated liquid is added with water, etc., to extract the alpha-naphthylacetic acid ester to an organic layer and the cobalt compound to an aqueous layer. The organic layer is hydrolyzed, pH of the obtained liquid is adjusted, the by-product is extracted at >=6.5pH, the liquid is decolored under nearly neutral condition and the objective compound is crystallized at 1.5-3.0pH. The precipitated compound is washed with water, dried and purified. |
