Reaktion #709941

Reaktionsgleichung

phosphorus pentachloride

7-(2-thienylacetamido)-3-(3-chloro-1-pyridiniomethyl)-3-cephem-4-carboxylate

N,N-dimethylaniline

1,3-butanediol

trimethylsilylchloride

→

7-amino-3-(3-chloro-1-pyridiniomethyl)-3-cephem-4-carboxylate dihydrochloride

Ausbeute 177.6%

Lösungsmittel

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGunder stirring
2. 2
   workup.WAITwhich was continued for one hour at -30° to -25° C
3. 3
   Temperaturunder cooling in an ice-bath
4. 4
   workup.STIRRINGstirring
5. 5
   workup.WAITwhich was continued for one hour at ambient temperature
6. 6
   FiltrationThe resulting precipitate was filtered
7. 7
   Waschenwashed with methylene chloride
8. 8
   workup.DISSOLUTIONredissolved in methanol (50 ml)
9. 9
   workup.ADDITIONAfter the solution was treated with activated charcoal (1 g)
10. 10
    workup.ADDITIONthe filtrate was poured into acetone (500 ml)
11. 11
    workup.STIRRINGunder stirring
12. 12
    workup.WAITwhich was continued for 30 minutes at ambient temperature
13. 13
    FiltrationThe resulting precipitate was filtered
14. 14
    Waschenwashed with acetone
15. 15
    Sonstigedried

Vorschrift

To a mixture of 7-(2-thienylacetamido)-3-(3-chloro-1-pyridiniomethyl)-3-cephem-4-carboxylate (22.5 g) and N,N-dimethylaniline (60.0 g) in methylene chloride (400 ml) was added dropwise trimethylsilylchloride (50.0 g) at ambient temperature under stirring, which was continued for 15 minutes at the same temperature. The reaction mixture was cooled to -30° C. and phosphorus pentachloride (31.2 g) was added thereto under stirring, which was continued for one hour at -30° to -25° C. The reaction mixture was added to a cold solution of 1,3-butanediol (45 g) in methylene chloride (400 ml) under cooling in an ice-bath and stirring, which was continued for one hour at ambient temperature. The resulting precipitate was filtered, washed with methylene chloride and redissolved in methanol (50 ml). After the solution was treated with activated charcoal (1 g), the filtrate was poured into acetone (500 ml) under stirring, which was continued for 30 minutes at ambient temperature. The resulting precipitate was filtered, washed with acetone and dried to give 7-amino-3-(3-chloro-1-pyridiniomethyl)-3-cephem-4-carboxylate dihydrochloride (17.7 g), mp. 160° to 165° C. (dec.).

Quelle