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US 4,267,321 AGranted
Cephalosporin derivatives
AssigneeSandoz Ltd.
InventorGerd Ascher
Life of this patent
Estimating the term…
Abstract
Novel Cephalosporin C derivatives, their production and their use in isolating Cephalosporin C from culture filtrates for subsequent conversion to 7-aminocephalosporanic acid.
Claims7
##STR7## in which each R.sub.1 independently represents hydrogen or an ester protecting group,
- and R.sub.2 and R.sub.3, each independently represent hydrogen, nitro, cyano or lower alkoxy carbonyl, or and alkali metal salt provided at least one R.sub.1 represents hydrogen.
Dependencies are inferred from the claim text.