జర్నల్ ఆఫ్ ఎనలిటికల్ & బయోఅనలిటికల్ టెక్నిక్స్

నైరూప్య

Isolation and Structural Elucidation of Novel Isomeric Process Related Impurities of Zolmitriptan

Neelakandan K, Chaudhari Ashok, Manikandan H, Santosha N, Prabhakaran B and Mukund Gurjar

Four isomeric unknown impurities ranging from 0.08-0.12% were found in the purified sample of Zolmitriptan during the batch analysis by gradient reverse phase ultra performance liquid chromatography (UPLC) and their molecular weights determined by liquid chromatography mass spectroscopy (LC-MS) analysis. Subsequently, all the four impurities were isolated by flash chromatography followed by semi-preparative HPLC and characterized by 1H NMR, 13C NMR, 1H-1H COSY, HMBC, HSQC, MS spectroscopy and HPLC. The structures for these four impurities were assigned to be following
Isomeric Impurity-1: 4-((3-(2-(dimethylamino)ethyl)-4-(2-((oxazolidin-4-yl)methyl)phenyl)-1H-indol-5-yl)methyl) oxazolidin-2-one,
Isomeric Impurity-2: 4-((3-(2-(dimethylamino)ethyl)-2-(4-((oxazolidin-4-yl)methyl)phenyl)-1H-indol-5-yl)methyl) oxazolidin-2-one-,
Isomeric Impurity-3: 4-((3-(2-(dimethylamino)ethyl)-7-(4-((oxazolidin-4-yl)methyl)phenyl)-1H-indol-5-yl)methyl) oxazolidin-2-one,
Isomeric Impurity-4: 4-((3-(2-(dimethylamino)ethyl)-6-(4-((oxazolidin-4-yl)methyl)phenyl)-1H-indol-5-yl)methyl) oxazolidin-2-one
Isolation and characterization of impurities has helped us in improving the purity of API by removing these impurities using crystallization.