Reaktion #94054

Reaktionsgleichung

7-phenoxyacetoamido-3-chloro-3-methyl-cepham-4-carboxylic acid p-nitrobenzylester

hydrogen

→

7-phenoxyacetoamido-3-chloro-3-methyl-cepham-4-carboxylic acid

Ausbeute 51.5%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationAfter the catalyst was filtered off from the reaction mixture
2. 2
   Extraktionthe filtrate was extracted with 50 ml of 2% aquous sodium hydrogencarbonate solution
3. 3
   SonstigeAfter the aqueous layer was separated
4. 4
   workup.ADDITIONby adding diluted hydrochloric acid
5. 5
   Extraktionthe aqueous layer was extracted again with ethyl acetate
6. 6
   WaschenThe ethyl acetate layer was washed with water
7. 7
   Sonstigedried
8. 8
   workup.DISTILLATIONdistilled under reduced pressure
9. 9
   SonstigeThere was obtained

Vorschrift

In 30 ml of ethyl acetate was dissolved 470 mg of 7-phenoxyacetoamido-3-chloro-3-methyl-cepham-4-carboxylic acid p-nitrobenzylester. To the solution was added 470 mg of 5% palladium-charcoal and the solution was stirred for 19 hours in a stream of hydrogen. After the catalyst was filtered off from the reaction mixture, the filtrate was extracted with 50 ml of 2% aquous sodium hydrogencarbonate solution. After the aqueous layer was separated and adjusted to pH 2 by adding diluted hydrochloric acid, the aqueous layer was extracted again with ethyl acetate. The ethyl acetate layer was washed with water, dried and distilled under reduced pressure. There was obtained 179 mg of 7-phenoxyacetoamido-3-chloro-3-methyl-cepham-4-carboxylic acid as a colourless powder (yield, 15%). The following NMR spectra agreed with those expected from the anticipated structure:

Quelle