Patent ID: 8598383

Claim:
A method for manufacturing 2-acetoxy-5-[2-(4-trifluoromethyl-phenyl)-ethylamino]-benzoic acid at yield rate of at least 92%, comprising (S1) reacting 2-hydroxy-5-[2-(4-trifluoromethyl-phenyl)-ethylamino]-benzoic acid with di-tert-butyl dicarbonate; (S2) reacting 5-{tert-butoxycarbonyl[2-(4-trifluoromethyl-phenyl)-ethyl]amino}-2-hydrox-ybenzoic acid, which is made in the (S1) step, with acetyl halide; and (S3) removing tert-butoxycarbonyl group from 5-{tert-butoxycarbonyl[2-(4-trifluoromethyl-phenyl)-ethyl]amino}-2-acetox-ybenzoic acid, which is made in the (S2) step.