Reaktion #460051

Reaktionsgleichung

ethyl acetate

diphenylmethyl 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylate

anisole

trifluoroacetic acid

→

benzylamine

collidine

7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylic acid

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe reaction mixture is concentrated at room temperature
2. 2
   Sonstigeobtained residue
3. 3
   Extraktionis extracted with aqueous sodium hydrogen carbonate solution
4. 4
   TemperaturThe extract aqueous solution is cooled with ice
5. 5
   Extraktionis extracted with ethyl acetate
6. 6
   WaschenThe extract solution is washed with water
7. 7
   Trocknendried over sodium sulfate
8. 8
   Einengenconcentrated to one third volume
9. 9
   workup.ADDITIONTo this solution is added an equivalent amount of collidine or benzylamine
10. 10
    Filtrationthe separated crystals are collected by filtration

Vorschrift

To a solution of diphenylmethyl 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylate (stereoisomer A: 58 mg) in methylene chloride (0.6 ml) are added anisole (0.12 ml) and trifluoroacetic acid (0.12 ml). After 15 minutes, the reaction mixture is concentrated at room temperature, and obtained residue is dissolved in ethyl acetate, and is extracted with aqueous sodium hydrogen carbonate solution. The extract aqueous solution is cooled with ice, stirred and neutralized with 1N-hydrochloric acid to pH 2, and is extracted with ethyl acetate. The extract solution is washed with water, dried over sodium sulfate, and concentrated to one third volume. To this solution is added an equivalent amount of collidine or benzylamine, and the separated crystals are collected by filtration to give 7-(2-thienylacetamido)-3-(1-acetoxyethyl)-3-cephem-4-carboxylic acid (stereoisomer A) collidine salt or benzylamine salt.

Quelle