During the synthesis of Sparfloxacin, a fluoroquinolone antibiotic drug, an unknown impurity (SF5-IMP) was identified in the fifth stage of the synthetic process. The impurity has been isolated from the mother liquor of intermediate SF5. The mother liquor was concentrated to dryness added dichloromethane and stirred for 1 h and filtered to generate SF5-IMP and the molecular structure was elucidated as 7-amino-1-cyclopropyl-5,6,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid by 19 F NMR and single crystal X-ray diffraction studies. The structural features of SF5-IMP and SF5 have been discussed here.
Two unknown impurities were detected in stressed samples (by hydrochloric acid and hydrogen peroxide) of paroxetine hydrochloride hemihydrate (an active pharmaceutical ingredient -API) using a gradient reversed-phase high performance liquid chromatography (HPLC). These impurities were enriched and were present up to 30% in the degraded sample. The impurities were isolated from the degraded sample by column purification. Spectral data of the isolated impurities were collected. Based on the spectral data of two dimensional nuclear magnetic spectroscopy (2D-NMR) and mass spectrometry (MS) Impurity-1 and Impurity-2 were characterized as (3S,4R)-3-{ [(6-chloro-1,3-benzodioxol-5-yl)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.