Hydrochloric Acid → (5-Methyl-2-oxo-1,3-dioxolen-4-yl)methyl 7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

Herkunft & Nachweise