[C:1]([NH:9][CH:10]1[C:22](=[O:23])[N:12]2[C:13]([C:19]([OH:21])=[O:20])=[C:14]([CH3:18])[CH2:15][S:16](=[O:17])[C@H:11]12)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CN([Si:32]([CH3:35])([CH3:34])[CH3:33])C(=O)C(F)(F)F.[Br:36]N1C(=O)CCC1=O>ClCCl>[C:1]([NH:9][CH:10]1[C:22](=[O:23])[N:12]2[C:13]([C:19]([O:21][Si:32]([CH3:35])([CH3:34])[CH3:33])=[O:20])=[C:14]([CH2:18][Br:36])[CH2:15][S:16](=[O:17])[C@H:11]12)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1To a suspension of 335 mg (1.00 mmole) of 7-benzamido-3-methyl-3-cephem-4-carboxylic acid-1-oxide in 25 ml of dichloromethane, 279 mg of N-methyl-N-trimethylsilyltrifluoroacetamide (1.40 mmoles) were added and the mixture was stirred for 10 minutes at room temperature to obtain a clear, yellow solution. This was cooled in an ice-bath and bromination was carried out in half an hour using 253 mg of N-bromosuccinimide (1.42 mmoles) as the brominating agent to obtain a yield of 52% of trimethylsilyl 7-benzamido-3-bromomethyl-3-cephem-4-carboxylate-1-oxide.
Wird geladen…