ISOLATION AND STRUCTURAL ELUCIDATION OF AN IMPURITY OF CEFRADINE

An impurity of unknown identity was isolated from commercial cefradine by liquid chromatography on poly (styrene-divinylbenzene) with HOAc ( 0.01 M)-CH3CN (94:6, v/v) as the mobile phase. The structure was eluci dated as 4',5'-dihydrocefradine using nuclear magnetic resonance spect roscopy (NMR) and mass spectrometry (MS). The structure was confirmed by comparison with the chromatographic retention characteristics and p hotodiode-array detected ultraviolet spectrum of the synthetic compoun d and with its infrared, NMR and MS spectra. The presence of 4',5'-dih ydrocefradine in cefradine has not been described previously.