반응 #94921

반응 방정식

trimethylchlorosilane

sodium cephalothin

monosilyltrifluoroacetamide

phenylacetyl chloride

→

7-(phenylacetyl-2-thienylacetyl)amino-3-acetoxymethyl-3-cephem-4-carboxylic acid

용매

반응 조건

후처리

1. 1
   기타fitted with a drying tube
2. 2
   기타The volatiles are evaporated
3. 3
   기타to afford a residue which
4. 4
   workup.DISSOLUTIONis dissolved in 100 ml
5. 5
   세척of ethyl acetate and washed three times with water
6. 6
   건조The ethyl acetate layer is dried over magnesium sulfate
7. 7
   여과filtered
8. 8
   기타the solution evaporated in vacuo to a residue
9. 9
   기타The residue is triturated with chloroform
10. 10
    기타any insolubles are removed by filtration
11. 11
    기타the product precipitated from the filtrate with hexane

실험 절차

A suspension of sodium cephalothin (3.36 g.) in anhydrous alcohol-free chloroform (20 ml.) is silylated by the addition of trimethylchlorosilane (2.2 ml.). After stirring for 30 minutes, monosilyltrifluoroacetamide (5.0 ml.) and phenylacetyl chloride (4.0 ml.) are added and the mixture is then heated to 45° C. for two days under a condenser fitted with a drying tube. The volatiles are evaporated to afford a residue which is dissolved in 100 ml. of ethyl acetate and washed three times with water. The ethyl acetate layer is dried over magnesium sulfate, filtered and the solution evaporated in vacuo to a residue. The residue is triturated with chloroform, any insolubles are removed by filtration and the product precipitated from the filtrate with hexane. This procedure is followed two more times. The 7-(phenylacetyl-2-thienylacetyl)amino-3-acetoxymethyl-3-cephem-4-carboxylic acid is obtained in a solvent-free form by freeze drying from a solution in benzene.

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