反应详情

A suspension of 2 g of poly-Hunig base in 8 ml of dioxan is stirred at room temperature for 30 minutes, a solution of 962 mg of 2-[(3S,4R)-4-acetylthio-3-phenoxyacetoxy-2-oxoazetidin-1-yl]-2-hydroxyacetic acid p-nitrobenzyl ester in 10 ml of dioxan is added, then a solution of 0.38 ml of thionyl chloride in 8 ml of dioxan is added slowly. The mixture is stirred for 2 hours at room temperature, the poly-H/e,uml/u/ nig base is filtered off and the filtrate is concentrated by evaporation in vacuo. The residue is purified by chromatography over silica gel with toluene/ethyl acetate (1:1) and yields the 2-[(3S,4R)-4-acetylthio-3-methoxy-2-oxoazetidin-1-yl]-2-chloroacetic acid p-nitrobenzyl ester in crude form.

1. stirringThe mixture is stirred for 2 hours at room temperature
2. filtrationthe poly-H/e,uml/u/ nig base is filtered off
3. concentrationthe filtrate is concentrated by evaporation in vacuo
4. customThe residue is purified by chromatography over silica gel with toluene/ethyl acetate (1:1)