PURPOSE: To readily obtain the subject high-quality compound in good yield by using crude methylnaphthalene as a raw material and continuously feeding a specific solvent and catalyst to a reaction system at a rate so as to provide a prescribed concentration or below of the raw material.
CONSTITUTION: Oxidative reaction of coal-based methylnaphthalene obtained from coal tar and/or an oxidation derivative thereof as a raw material with molecular O2 is carried out in the liquid phase in the presence of a catalyst containing at least one heavy metal selected from Co and Mn and Br2 in a solvent containing acetic acid by continuously adding the raw material into the solvent containing the above-mentioned catalyst at a rate so as to provide ≤0.1mol methylnaphthalene concentration in the reaction system based on 1g-atom total amount of heavy metal atom present in the aforementioned solvent according to a continuous or discontinuous method to simplify purifying operation and efficiently, industrially and advantageously afford the objective compound useful as a dye, pigment, photographic chemical, etc., at a low cost.
ITO IKUO
TAKEDA KYOICHI
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