反応 #214636

反応方程式

2-[4-(p-toluenesulphonylthio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid p-nitrobenzyl ester

sodium bisulphite

→

2-[4-(p-toluenesulphonylthio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid p-nitrobenzyl ester

溶媒

ethyl acetate

methyl acetate

water

反応条件

後処理

1. 1
   その他ozonised at -70° C.
2. 2
   温度the latter is warmed to 0°-5° C
3. 3
   その他the aqueous phase is separated off
4. 4
   洗浄the organic phase is washed with water
5. 5
   乾燥dried over magnesium sulphate
6. 6
   workup.DISSOLUTIONThe crude product is dissolved in 3 ml of methylene chloride
7. 7
   workup.ADDITION15 ml of toluene are added
8. 8
   ろ過The precipitate is filtered off
9. 9
   濃縮the filtrate is concentrated by evaporation in vacuo
10. 10
    その他The residue is recrystallised from methanol

実験手順

(di) The crude 2-[4-(p-toluenesulphonylthio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid p-nitrobenzyl ester obtained according to Example (1.cvii) is dissolved in 20 ml of methyl acetate and ozonised at -70° C. until starting material is no longer present, according to a thin layer chromatogram. A stream of nitrogen is then passed through the solution and the latter is warmed to 0°-5° C. A solution of 300 mg of sodium bisulphite in 5 ml of water is added and the mixture is stirred for about 5 minutes until no further ozonide is detectable by means of potassium iodide/starch paper. The mixture is diluted with ethyl acetate, the aqueous phase is separated off and the organic phase is washed with water, dried over magnesium sulphate and freed from the solvent in vacuo. The crude product is dissolved in 3 ml of methylene chloride and 15 ml of toluene are added. The precipitate is filtered off and the filtrate is concentrated by evaporation in vacuo. The residue is recrystallised from methanol and gives 2-[4-(p-toluenesulphonylthio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid p-nitrobenzyl ester of melting point 159°-160° C.

出典