Abstract

The present study aimed at synthesizing the process related potential impurities of aceclofenac. Aceclofenac is an orally administered phenyl acetic acid derivative with effects on a variety of inflammatory mediators. Process related impurities of aceclofenac listed in British Pharmacopoeia have been synthesized by modified methods and characterized by FT IR, MS and ¹H NMR data. Impurity A: [2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid (diclofenac) was synthesized by acid hydrolysis of diclofenac sodium; Impurity B: methyl [2-[(2,6-dichlorophenyl) amino] phenyl]acetate (methyl ester of diclofenac); Impurity C:Ethyl [2-[(2,6-dichlorophenyl) amino] phenyl]acetate (ethyl ester of diclofenac); Impurity D: methyl [[[2-[(2,6-dichlorophenyl) amino] phenyl] acetyl] oxy]acetate (methyl ester of aceclofenac) and Impurity E: ethyl [[[2-[(2,6-dichlorophenyl) amino]phenyl] acetyl] oxy]acetate (ethyl ester of aceclofenac) were sythesized by simple and convenient direct methylation and ethylation of diclofenac and aceclofenac respectively instead of tedious esterification process. Impurity F: benzyl [[[2-[(2,6-dichlorophenyl) amino] phenyl] acetyl] oxy] acetate (benzyl ester of aceclofenac) was synthesized by condensation of diclofenac sodium with benzylbromoacetate. Impurity I:1-(2,6-dichlorophenyl)-1,3-dihydro-2H-indol-2-one was synthesized by acid cyclization of diclofenac. The present study has provided an efficient method for synthesis of process related aceclofenac impurities.

Keywords

Aceclofenac, Impurity, Synthesis, Characterization