SOLID ACID CATALYST

PROBLEM TO BE SOLVED : To provide a new production method and a catalyst which does not require a reduction of waste products, a simplification of separation processes and a high-quality reactor which materials are acid resistant in production accompanied with a Friedel-Crafts reaction. SOLUTION : An aromatic compound having a carbonyl group with a Friedel-Crafts reaction by reacting an aromatic compound, an ester compound or an olefin under presence of a solid acid catalyst containing a rare earth metal salt of sulfonic acid and silica-based inorganic material, especially tetralones or alkylated or alkenylated aromatic compounds is produced by one stage reaction.