Dichloromethane → 3-[(Acetyloxy)-methyl]-7-[[2-[4-(chloromethyl)phenyl]-2-carboxyacetyl]-amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Beteiligte Stoffe

Reaktionsschritte

α -Carboxy-p-chloromethylphenylacetyl nitrophenyl polymer, prepared according to the procedure described in Canadian Pat. No. 892,580, carrying 4 m. mole of α-chloromethylphenylmalonic acid is stirred for about 8 hours in 20 ml of dry methylene chloride solution containing 1 m. mole of 3-[(acetyloxy)methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid triethylammonium salt, which is prepared from 544 mg of 7-aminocephalosporanic acid (1 m. mole) and 0.56 ml of triethylamine (1 m. mole) at room temperature. After only traces of 7-aminocephalosporanic acid remain in solution, which is determined by thin layer chromatography on cellulose in 70% aqueous propanol, the polymer is filtered off and washed with 3 portions of 50 ml each of methylene chloride. The combined filtrates are evaporated and the residue is dissolved in 20 ml of distilled water. This solution is acidified to pH 2 by adding 0.2N hydrochloric acid and extracted twice with ethyl acetate. The organic solution is dried over sodium sulfate and evaporated at room temperature. The reamaining solid is dried over night over phosphorus pentoxide under vacuum to give 3-[(acetyloxy)methyl] -7-[[2-[4-(chloromethyl)phenyl]-2-carboxyacetyl]amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid.

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