PROCESS OF THE PREPARATION OF 5-(SUBSTITUTED PHENYLALKYL)AMINO SALICYLIC ACID DERIVATIVES

摘要

Provided is a method for preparing a 5-(substituted phenylalkyl)aminosalicylic acid compound from an alkyl 5-(substituted phenylalkyl)aminosalicylate as an intermediate to improve yield by preventing the generation of monomers and to lower cost. The method comprises the step of reacting an alkyl 5-(substituted phenylalkyl)aminosalicylate represented by the formula II with HCl to prepare a 5-(substituted phenyalkyl)aminosalicylic acid compound represented by the formula I by hydrolysis, wherein R is H, a halogen atom, a haloalkyl group, a nitro group, a hydroxy group, an alkyl group, an aryl group, an alkoxy group or an amine group; n is 1 or 2; A is H or an alkyl group; and B is H or an acetyl group. The alkyl 5-(substituted phenylalkyl)aminosalicylate of the formula II is prepared by reacting an R-substituted 2-phenyl acetaldehyde or 3-phenylpropyl aldehyde with 5-aminosalicylic acid by reductive amination.