2-Chlorobenzoyl chloride reacts with aromatic amines and ammonium thiocyanate using polyethylene glycol-400 as the catalyst under the condition of solid-liquid phase-transfer catalysis to form N-aryl-N′(2-chlorobenzoyl) thioureas. 2-Chlorobenzoyl chloride causes the acylation of polystyrene during the preparation and regeneration of the polystyrene-based resin.