Reaktion #5620

Reaktionsgleichung

formic acid

trifluoroacetic acid

7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-4-tert-butoxycarbonyl-1-piperazinio)methyl-3-cephem-4-carboxylate hydrochloride

→

7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-1-piperazinio)methyl-3-cephem-4-carboxylate

Ausbeute 33.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe resulting precipietes were collected by filtration
2. 2
   workup.ADDITIONadded to water
3. 3
   Filtrationfiltered
4. 4
   SonstigeThe eluate was evaporated in vacuo
5. 5
   Sonstigeto remove isopropanol

Vorschrift

To a mixture of formic acid (10 ml) and trifluoroacetic acid (5 ml) was added 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-4-tert-butoxycarbonyl-1-piperazinio)methyl-3-cephem-4-carboxylate hydrochloride (syn isomer) (5.7 g) at 20° C. under stirring. The stirring was continued for 1.5 hours at the same temperature. The reaction mixture was poured into ethyl acetate (200 ml). The resulting precipietes were collected by filtration, added to water. The mixture was adjusted to pH 2.0 with a saturated aqueous solution of sodium bicarbonate and filtered. The filtrate was subjected to column chromatography on Diaion HP-20 using 10% aqueous isopropanol as an eluent. The eluate was evaporated in vacuo to remove isopropanol and then lyophilized to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-carboxymethoxyiminoacetamido]-3-(1-methyl-1-piperazinio)methyl-3-cephem-4-carboxylate (syn isomer) (1.50 g).

Quelle