반응 #54376

반응 방정식

toluene ethyl acetate

2-[4-(benzoxazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester

ozone

O2 O3

→

2-[4-(Benzoxazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester

용매

ethyl acetate

반응 조건

후처리

1. 1
   농축The solution is concentrated by evaporation to about 50 ml in vacuo
2. 2
   workup.ADDITIONmixed with 5 ml of dimethyl sulphide
3. 3
   기타no longer gives
4. 4
   기타a reaction
5. 5
   농축The mixture is concentrated by evaporation in vacuo
6. 6
   workup.DISSOLUTIONthe residue is dissolved in 150 ml of benzene
7. 7
   세척the solution is washed with water
8. 8
   건조The organic phase is dried over sodium sulphate
9. 9
   농축concentrated by evaporation
10. 10
    기타The residue is chromatographed on 150 g of acid-washed silica gel

실험 절차

(aix) Approximately one equivalent of ozone (in the form of an O2 /O3 mixture) is passed into a solution, cooled to -70° C., of 3.35 g of 2-[4-(benzoxazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-methylene-butyric acid diphenylmethyl ester in 125 ml of ethyl acetate, until starting material is no longer detectable by thin layer chromatography (silica gel; toluene/ethyl acetate, 3:1). The solution is concentrated by evaporation to about 50 ml in vacuo, mixed with 5 ml of dimethyl sulphide and stirred until the potassium iodide/starch test no longer gives a reaction. The mixture is concentrated by evaporation in vacuo, the residue is dissolved in 150 ml of benzene and the solution is washed with water. The organic phase is dried over sodium sulphate and concentrated by evaporation. The residue is chromatographed on 150 g of acid-washed silica gel, using toluene/ethyl acetate, 4:1. 2-[4-(Benzoxazol-2-yldithio)-3-phenoxyacetamido-2-oxoazetidin-1-yl]-3-hydroxy-crotonic acid diphenylmethyl ester is obtained in the form of a white foam; IR spectrum (methylene chloride): characteristic bands at 5.60, 5.90 and 6.0 μ.

출처