PURPOSE: To efficiently obtain the subject compound in high yield and high purity with ready and simple operation in low cost by using methylnaphthalene previously subjected to specific treatment before reaction as a raw material and oxidizing in liquid phase with molecular O2 in the presence of a specific solvent and a specific catalyst.
CONSTITUTION: Methylnaphthalene of a low cost obtained from coal tar is used as a raw material and previously treated with at least one selected from alkali metal such as metallic Na in an amount of 0.1-3wt.% of methylnaphthalene and Lewis acid such as AlCl3 in an amount of 0.5-5wt.% for 10 min - several hour before reaction, then oxidized in liquid phase with introducing molecular O2 in a solvent containing acetic acid and in the presence of a catalyst composed of at least one heavy-metal compound selected from Co in cobalt acetate, etc., and Mn in manganese acetate, etc., and a bromine compound such as KI at 80-240°C for 0.5-5 hour under air pressure of ≤ several tens atm., to afford the aimed compound useful for dye, pigment or photographic agent, etc.
ITO IKUO
TAKEDA KYOICHI
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