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US 4,045,435 AGranted
Preparation of cephalosporin ethers
AssigneeEli Lilly and Company
InventorGary A. Koppel
Life of this patent
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Abstract
Reaction of 3-hydroxy cephalosporins with alkylfluorosulfonates in the presence of a base provides 3-alkoxy cephalosporins which are useful as intermediates for cephalosporin antibiotic preparation.
Claims5
A process for preparing a cephalosporin ether of the formula ##STR5## wherein:
- R.sub.1 is C.sub.1-C.sub.4 alkyl;
- R.sub.2 is a readily removable ester forming group;
- and
- R.sub.3 is a carboxylic acid acyl residue selected from the group consisting of ##STR6## wherein:
- R.sub.4 is 1,4-cyclohexadienyl, phenyl, or phenyl substituted by chlorine, bromine, fluorine, iodine, hydroxy, nitro, amino, cyano, C.sub.1 -C.sub.4 alkyl, C.sub.1 C.sub.4 alkoxy, Y is O or S, and m is zero or one;
- R.sub.5 is R.sub.4, 2-thienyl, or 3-thienyl;
- Z is protected hydroxy or protected amino;
- R.sub.6 is 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, 5-tetrazolyl, 2-thiazolyl, or 2-oxazolyl;
- comprising treating a 7-acylamido-3-hydroxy-3-cephem-4-carboxylic acid ester with a non-hydroxylic base selected from the group consisting of alkali metal amides, alkali metal hydride, alkali metal alkoxides, alkali metal triphenylmethides, butyl lithium, phenyl lithium, and sodium dimsyl,
- and a C.sub.1 -C.sub.4 alkylfluorosulfonate in an unreactive organic solvent.
7 more elements
Dependencies are inferred from the claim text.