反応 #95238

反応方程式

trimethylchlorosilane

sodium cephalothin

monosilyltrifluoroacetamide

phenylacetyl chloride

→

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

溶媒

反応条件

後処理

1. 1
   その他fitted with a drying tube
2. 2
   その他The volatiles are evaporated
3. 3
   その他to afford a residue which
4. 4
   workup.DISSOLUTIONis dissolved in 100 ml
5. 5
   洗浄of ethyl acetate and washed three times with water
6. 6
   乾燥The ethyl acetate layer is dried over magnesium sulfate
7. 7
   ろ過filtered
8. 8
   その他the solution evaporated in vacuo to a residue
9. 9
   その他The residue is triturated with chloroform
10. 10
    その他any insolubles are removed by filtration
11. 11
    その他the product precipitated from the filtrate with hexane

実験手順

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.

出典