Reaktion #62546

Reaktionsgleichung

4-bromo-methyl-5-methyl-1,3-dioxolene-2-one

HCl

7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid

propylene oxide

→

title compound

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

Lösungsmittel

EtOAc

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe EtOAc layer was separated
2. 2
   Waschenwashed successively with aq HCl (pH 3) (70 ml×2), 10% K2HPO4 buffer (pH 7) (70 ml×2) and saturated aq NaCl (50 ml)
3. 3
   TrocknenThe EtOAc solution was dried (MgSO4)
4. 4
   Einengenconcentrated in vacuo
5. 5
   SonstigeThe residue was triturated with ether (300 ml)
6. 6
   Filtrationthe resulting precipitate was filtered

Vorschrift

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).

Quelle