Synthesis of dinitrophenyl-l-Pro-N-hydroxysuccinimide ester and four new variants of Sangerʹs reagent having chiral amines and their application for enantioresolution of mexiletine using reversed-phase high-performance liquid chromatography

Four chiral derivatizing reagents (CDRs) having enantiomerically pure amines and two CDRs namely, [N-succinimidyl-(S)-2-(6-methoxynaphth-2-yl)propionate], and [dinitrophenyl-l-Pro-N-hydroxysuccinimide ester, DNP-l-Pro-SU] were synthesized and were used to prepare diastereomers of (R,S)-mexiletine (MEX); these were separated by reversed-phase high-performance liquid chromatography (RP-HPLC). The method was validated for linearity, accuracy, limit of detection (LOD) and limit of quantification (LOQ).