反应详情

In 240 ml of dichloromethane is suspended 9.06 g of 7β-amino-3-(3-oxobutyryloxymethyl)-3-cephem-4-carboxylic acid. To the suspension is added 28.9 g of bistrimethylsilylacetamide and the mixture is stirred at room temperature until complete dissolution and cooled in an ice-water bath. To this solution, 2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetyl chloride hydrochloride prepared from 5.83 g of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-methoximinoacetic acid and 6.02 g of phosphorus pentachloride in 90 ml of dichloromethane is added and the mixture is stirred for a while. The whole mixture is stirred with ice-cooling for 60 minutes. The dichloromethane is evaporated off and the residue is dissolved in methyl ethyl ketone. The solution is washed with water and dried. The solvent is then evaporated off and diethyl ether is added to the residue to give a fine precipitate, which is collected by filtration, giving 11.8 (82% yield) g of the title compound.

1. temperaturecooled in an ice-water bath
2. additionis added
3. stirringthe mixture is stirred for a while
4. stirringThe whole mixture is stirred with ice-
5. temperaturecooling for 60 minutes
6. customThe dichloromethane is evaporated off
7. dissolutionthe residue is dissolved in methyl ethyl ketone
8. washThe solution is washed with water
9. customdried
10. customThe solvent is then evaporated off
11. additiondiethyl ether is added to the residue
12. customto give a fine precipitate, which
13. filtrationis collected by filtration