反应详情

温度

5 °C

A suspension of 7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid (1.07 g, 3 mmole), KHCO3 (1.0 g, 10 mmole) and propylene oxide (1 ml) in DMF (5 ml) was cooled to 5° C. and treated with 4-bromo-methyl-5-methyl-1,3-dioxolene-2-one (0.87 g, 4.5 mmole). After stirring at 5° C. for 5 hr, the reaction mixture was poured into a mixture of aq HCl (pH 3) (70 ml) and EtOAc (250 ml). The EtOAc layer was separated and washed successively with aq HCl (pH 3) (70 ml×2), 10% K2HPO4 buffer (pH 7) (70 ml×2) and saturated aq NaCl (50 ml). The EtOAc solution was dried (MgSO4) and concentrated in vacuo. The residue was triturated with ether (300 ml) and the resulting precipitate was filtered to give the title compound ( 0.45 g).

1. customThe EtOAc layer was separated
2. washwashed successively with aq HCl (pH 3) (70 ml×2), 10% K2HPO4 buffer (pH 7) (70 ml×2) and saturated aq NaCl (50 ml)
3. dry with materialThe EtOAc solution was dried (MgSO4)
4. concentrationconcentrated in vacuo
5. customThe residue was triturated with ether (300 ml)
6. filtrationthe resulting precipitate was filtered