反应详情

A 2.0 g quantity of benzyl 2-(3-phenoxyacetamido-4-benzenesulfonylthio-2-azetidinone-1-yl)-3-methyl-3-butenate was dissolved in 10 ml of dichloromethane and to the solution was added 5 to ml of water. The mixture was cooled in an ice bath with stirring while thereto was added dropwise over 30 minutes about 10 ml of methylene chloride having dissolved therein 6.9 mmol of chlorine gas. After the addition, the organic layer was separated and the aqueous layer was extracted with dichloromethane. The organic layer thus separated and the dichloromethane layer were washed successively with aqueous solutions each of NaHCO3, Na2S2O3 and NaCl and dried over anhydrous magnesium sulfate. The solvent was distilled off at reduced pressure. The resulting residue was separated and purified by silica gel column chromatography, giving 1.87 g of benzyl 2-(3-phenoxyacetamido-4-benzenesulfonylthio-2-azetidinone-1-yl)-3-chloromethyl-3-butenate in 88% yield.

1. temperatureThe mixture was cooled in an ice bath
2. dissolutiondissolved
3. additionAfter the addition
4. customthe organic layer was separated
5. extractionthe aqueous layer was extracted with dichloromethane
6. customThe organic layer thus separated
7. washthe dichloromethane layer were washed successively with aqueous solutions each of NaHCO3, Na2S2O3 and NaCl
8. dry with materialdried over anhydrous magnesium sulfate
9. distillationThe solvent was distilled off at reduced pressure
10. customThe resulting residue was separated
11. custompurified by silica gel column chromatography