GC method for separation and quantification of positional isomers of trifluoro methoxy aniline and trifluoromethoxy nitro benzene in 4-(trifluoromethoxy aniline), a key intermediate of Riluzole

A.Nageswari, P.Surya Prakash R

Abstract

A sensitive and simple GC method was developed for the separation and quantification of related impurities in 4-(trifluoromethoxyAniline) (4-TFMA), which is a key intermediate of Riluzole. The analysis was performed by using FIDdetector andAT-210, 30meters, 0.53mminternal diameter and 1.0 µm GC capillary column with 3.0 psi pressure. In 4-TFMA, two more positional isomers like 3-TFMA and 2-TFMA were possible impurities, at the same time, its intermediate nitro compound also contains three positional isomers, like 2-nitro, 3-nitro and 4-nitro, also there is a possibility of two more intermediates like trifluoromethoxy benzene (TMB) and also its starting material anisole as an impurities.Asingle analytical method was developed for the separation of all theses impurities including six positional isomers with the quantitation and detection limits of less than 4g mL-1and 0.8g mL-1 respectively. TheAnalytical method was validated as per ICH.