Reaktion #64274

Reaktionsgleichung

loracarbef

ethyl paraben

H2O

hydrochloric acid

→

Loracarbef DMF

Ausbeute 98.4%

Lösungsmittel

triethylamine

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe pH was raised from 1.84 to 4.0 over 45 minutes
2. 2
   SonstigeAfter crystallization
3. 3
   workup.ADDITIONtriethylamine was slowly added until a pH of 6.7
4. 4
   Sonstigewas obtained
5. 5
   Filtrationfiltered
6. 6
   Waschenwashed with DMF and ethanol
7. 7
   Sonstigedried under vacuum at 40° C

Vorschrift

To loracarbef:ethyl paraben (15.0 g, 49.1% potency as loracarbef), predisolved in 150 ml DMF and 15 ml H2O was added concentrated hydrochloric acid (2.53 ml) dropwise. The solution was heated to 45° C. and the pH was raised from 1.84 to 4.0 over 45 minutes using triethylamine. After crystallization began, triethylamine was slowly added until a pH of 6.7 was obtained. The mixture was stirred for 1 hour at 45° C., filtered, washed with DMF and ethanol and dried under vacuum at 40° C. HPLC analysis indicated that no ethyl paraben was present. The actual yield was 10.07 g, 72% as loracarbef activity, the theoretical yield was 7.37 g of loracarbef activity, and the percent yield was 98.4% yield.

Quelle