反应详情

In 200 ml of dichloromethane is suspended 11 g of 7β-amino-3(3-oxobutyryloxymethyl)-3-cephem-4-carboxylic acid. To the suspension is added 14 g of bistrimethylsilylacetamide and the mixture is stirred at room temperature until complete dissolution and cooled in an ice-water bath. To this solution, 14 g of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-ethoxyiminoacetyl chloride is added and the mixture is stirred for a while, to which 6 g of dimethylacetamide is added. 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 12.5 g of the above-identified compound.

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