Patent ID: 8686185
Filing Date: 2014-04-01
Classification: C07C

Abstract:
1. A method for preparing 2-hydroxy-5-phenylalkylaminobenzoic acid derivative represented by Chemical formula 4 or its salt at a purity of at least 99%, comprising a step of preparing alkyl 2-hydroxy-5-phenylalkylaminobenzoate represented by Chemical formula 3 by reacting phenylalkyl methanesulfonate represented by Chemical formula 1 with alkyl 5-aminosalicylate represented by Chemical formula 2: wherein in the Chemical formulas 1 to 4, n is an integer from 2 to 4; R wherein the method comprises hydrolyzing alkyl 2-hydroxy-5-phenylalkylaminobenzoate represented by Chemical formula 3 to form 2-hydroxy-5-phenylalkylaminobenzoic acid sulfate; wherein the method comprises controlling the pH of the 2-hydroxy-5-phenylalkylaminobenzoic acid sulfate for purification; and wherein the purity of the 2-hydroxy-5-phenylalkylaminobenzoic acid derivative represented by Chemical formula 4 or its salt is at least 99%.