反应详情

In chloroform (70 ml) are dissolved 2,2,2-trichloroethyl 3-methyl-7-oxo-3-cephem-4-carboxylate (14.30 g), t-butyl carbazate (6.00 g) and pyridine hydrochloride (4.77 g) and the mixture is refluxed in a Dean-Stark trap packed with Molecular Sieve 3A for 30 minutes. The reaction mixture is washed with 1 N-HCl and water in that order, dried over magnesium sulfate and concentrated. The residual oil is subjected to silica gel (240 g) column chromatography and elution is carried out with ethyl acetate-benzene to give crystals of 2,2,2-trichloroethyl (E)-7-t-butoxycarbonylhydrazono-3-methyl-3-cephem-4-carboxylate (4.88 g).

1. temperaturethe mixture is refluxed in a Dean-Stark trap
2. washThe reaction mixture is washed with 1 N-HCl and water in that order
3. dry with materialdried over magnesium sulfate
4. concentrationconcentrated
5. washThe residual oil is subjected to silica gel (240 g) column chromatography and elution