Improvement on the Synthesis Method of 2-(4′-aminobenzoyl)benzoic Acid

2-(4′-Acetylaminobenzoyl)benzoic acid(1) was synthesized by Friedel-Crafts reaction from o-phthalic anhydride and acetanilide using AlCl_3 as a catalyst and 1,2-dichlorethene as a solvent.2 was obtained from 1 in acid solution by removing acetyl.The structures of 1 and 2 were characterized by ~1HNMR,IR,MS and elemental analysis.The optimal Friedel-Crafts reaction conditions were as follows: o-phthalic anhydride was 20 mmol;n(o-phthalic anhydride) ∶n(acetanilide) was(1 ∶1);n(o-phthalic anhydride) ∶n(AlCl_3) was 1 ∶3;45 ℃ for 1.5 h;the yield was 70.4%.