Chromatographic Separation and Identification of Related Impurities in Preparation of Clarithromycin through Reaction of Silyl-Etherification

OBJECTIVE Separation and identification of related impurities in preparation of clarithromycin through reaction of silyl-etherification.METHODSThe separation condition of impurities was optimized by TLC at first,Separation and purification of the related impurities were conducted by column chromatograph.HPLC chromatograph condition was established.The related impurities in the silyl-etherification were idertified by using 1H-NMR and MALDI-TOF-MS. RESULTSThe related impurities were confirmed as 4"-O-trimethylsilyl erythromycin A oxime (4) and 4"-O-trimethylsilyl erythromycin A 9(o-t-butyldimethylsilyl) oxime (5) by chromatography and spectroscopy. CONCLUSIONThe method could efficiently controll and monitor the quality of clarithromycin preparation in the silyl-etherification procedure.