IDENTIFICATION AND CHARACTERIZATION OF E, Z ISOMERS FOR ACID DEGRADENTS OF SECONDARY ALCOHOL IN API BY HS/GC/ EI-MS

2º alcohols under acidic conditions (such as sulphuric acid) undergo degradation into E & Z isomers. There are many drug substances with sulphate as salt, and sulphuric acid is used for the preparation of sulphate of drug substance. Also, sulphuric acid is widely used in synthetic process for many drug substances. 2º alcohols are widely used as process solvents and as crystallization solvents. Loss of solvents is very high, when 2º alcohols used as crystallization solvent and drug substance will have high crystalline stability. Flash points of 2º alcohols are comparatively higher than other solvents such as methanol, ethanol, benzene, dichloromethane and many other volatile solvents resulting into better fire safety for reactions and also lower exposure limits. Residual odour while drying of drug substance is minimum. 2º alcohols possess very low practical handling difficulties. For all these reasons, 2º alcohols are the preferred choice as process solvents and crystallization solvent. However and unfortunately when these 2º alcohols and sulphuric acids used together in a reaction, 2º alcohols undergo degradation into their E & Z isomers, the impact of these E & Z isomers on drug substance are unknown, hence, they need to be evaluated.