| 摘要 |
PURPOSE:To obtain the subject ester compound in high purity from a substituted naphthalene through naphthalene carboxylic acid thereof by recovering a heavy metal catalyst used in the production of subject ester compound with high yield after the esterification from the filtered solution and/or the washed solution as a carbonate. CONSTITUTION:Substituted naphthalene is oxidized by molecular oxygen in a solvent containing a lower aliphatic monocarboxylic acid and in the presence of a noble metal catalyst to obtain a crude naphthalene carboxylic acid containing the noble metal catalyst. Next, a resultant crude naphthalene carboxylic acid is esterified in an alkylalcohol and in the presence of an esterification catalyst and a resultant reaction product is filtered, a resultant filtered solution and/or resultant esterified substance is washed at least with >=1 kinds among water, an aqueous solution of acid or alkylalcohol, then a compound generating carbonate ion is added to the resultant washed solution or the concentrated solution thereof to convert dissolved heavy metal catalyst to an insoluble carbonate and is recovered in a high yield to make possible to use circularly for industrially advantageous production of the subject compound useful as a raw material for photographic agent or dye, etc., in high purity. |
