PURPOSE: To produce the titled substance, by dissolving acetyl chloride and AlCl3 catalyst at a specific ratio in a chlorinated hydrocarbon solvent, adding a chlorinated hydrocarbon solution of naphthalene to the above solution under cooling below a specific temperature, and treating the reaction liquid with dilute hydrochloric acid.

CONSTITUTION: An acetylation reaction liquid is prepared beforehand by dissolving 1mol of acetyl chloride and 1.0W1.2mol of AlCl3 in a chlorinated hydrocarbon solvent (preferably ethylene dichloride), and cooled at ≤10°C. Separately, about 1mol of naphthalene is dissolved in a chlorinated hydrocarbon solvent, and the solution is added slowly to the above solution while cooling the system to ≤10°C to effect the reaction. The liquid produced by the reaction is made to contact with dilute hydrochloric acid to decompose the acetylnaphthalene-aluminum chloride complex and obtain the titled substance.

EFFECT: The object substance can be produced economically in high purity.

USE: Precursor of optical resolution agent, etc.