반응 #94973

반응 방정식

trimethylchlorosilane

sodium cephalothin

monosilyltrifluoroacetamide

2-thienylacetyl chloride

→

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

용매

chloroform

—

alcohol

반응 조건

후처리

1. 1
   workup.WAITto remain at this temperature for two days
2. 2
   기타evaporated in vacuo to a residue which
3. 3
   workup.DISSOLUTIONis dissolved in ethyl acetate (50 ml.)
4. 4
   세척washed three times with water
5. 5
   건조The ethyl acetate layer is dried over magnesium sulfate
6. 6
   여과filtered
7. 7
   기타the filtrate evaporated in vacuo
8. 8
   기타to obtain a residue
9. 9
   기타precipitated with hexane three times

실험 절차

A suspension of sodium cephalothin (1.18 g.) in anhydrous alcohol-free chloroform (10 ml.) is silylated by the addition of trimethylchlorosilane (1.1 ml.). After stirring for 30 minutes, monosilyltrifluoroacetamide (2.5 ml.) and 2-thienylacetyl chloride (2.0 ml.) are added to the suspension which is then heated to 45° C. The mixture is allowed to remain at this temperature for two days and then evaporated in vacuo to a residue which is dissolved in ethyl acetate (50 ml.) and washed three times with water. The ethyl acetate layer is dried over magnesium sulfate, filtered and the filtrate evaporated in vacuo to obtain a residue. The residue is dissolved in chloroform and precipitated with hexane three times, each time discarding the supernatent liquid. The 7-(di-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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