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US 4,400,503 AGranted
Purification of syn-7-[[(2-amino-4-thiazolyl)(methoxyimino) acetyl]amino]-3-methyl-3-cephem-4-carboxylic acid
AssigneeEli Lilly and Company
InventorKuo S. Yang
Life of this patent
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Abstract
Crystalline cephalosporin hydrochloride salt represented by the formula ##STR1## wherein the oxime is in the syn configuration, is a useful pharmaceutical form of, and tool for purification of, the corresponding antibiotic free base; processes for its preparation are provided.
Claims4
The process for purifying the compound of formula 2:
- ##STR4## wherein the oxime is in the syn configuration which comprises preparing the crystalline hydrochloride salt of the formula 2 compound by (a) adding this compound to a solvent selected from water or a polar organic solvent to form a solution or slurry;
- (b) adding hydrochloric acid to give a solution which has a pH of between about 1.5 and 3.5;
- (c) maintaining the solution until crystallization occurs;
- (d) separating the crystalline salt;
- (e) dissolving the crystalline salt in an aqueous bicarbonate solution with the pH maintained between about 6 and about 7;
- (f) filtering the solution to separate solid impurities;
- and (g) adding hydrochloric acid to the filtered solution until free base of formula 2 precipitates.
4 more elements
Dependencies are inferred from the claim text.