Method for producing 1,4-dimethylnaphthalene

A method for producing 1,4-dimethylnaphthalene, comprising:

• cyclizing 5-phenyl-2-hexene in the presence of an acid catalyst to prepare crude 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene, dehydrogenizing the crude 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene to obtain a crude 1,4-dimethylnaphthalene, and purifying the crude 1,4-dimethylnaphthalene by distillation, wherein in this production method, the acid catalyst is a sulfonic acid or an amorphous silica-alumina catalyst, and the cyclization reaction takes place in a liquid phase at a temperature of 200° C. or lower to make a concentration of 1,3-dimethyl-1,2,3,4-tetrahydronaphthalene in 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene be 1.0% or less with respect to 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene, and
• wherein a concentration of 1,3-dimethylnaphthalene in 1,4-dimethylnaphthalene is 1.0% or less with respect to 1,4-dimethylnaphthalene.