1Dr. Reddy's Laboratories Limited, API Plant, Bollaram-III, Plot No 116, IDA Bollaram, Medak District, Hyderabad, 502325, Telangana, India
2Centre for Chemical Sciences and Technology, Institute of Science and Technology, Jawaharlal Nehru Technological University, Hyderabad, Kukatpally, Hyderabad, 500085, Telangana, India
Olanzapine key starting material, 5-methyl-2-((2-nitrophenyl)amino)thiophene-3-carbonitrile (3), is a key starting material of Olanzapine. During the impurity profile study an unknown peak was detected by HPLC and MS methods. Identification, isolation and structural characterization in olanzapine key starting material is described in this article. The impurity was isolated by preparative HPLC, Based on the complete spectral analysis, MS, 1D NMR (1H and 13C) and 2D NMR (COSY, HSQC and HMBC) the chemical structure of unknown impurity was characterized as 2-(bis(2-nitrophenyl)amino)-5-methylthiophene-3-carbonitrile.
Liquid chromatography-mass spectrometry, NMR, Characterization, impurity profile, Olanzapine