Cefroxadine
Template:Short description Template:Drugbox Cefroxadine (INN, trade names Oraspor and Cefthan-DS) is a cephalosporin antibiotic. It is structurally related to cefalexin, and both drugs share a similar spectrum of activity.[1]
It is available in Italy.[2]
Synthesis
Cefroxadine can be prepared by several routes, including one in which the enol is methylated with diazomethane as a key step. A rather more involved route starts with comparatively readily available phenoxymethylpenicillin sulfoxide benzhydryl ester (1).
This undergoes fragmentation when treated with benzothiazole-2-thiol to give 2. Ozonolysis (reductive work-up) cleaves the olefinic linkage and the unsymmetrical disulfide moiety is converted to a tosyl thioester (3). The enol moiety is methylated with diazomethane, the six-membered ring is closed by reaction with 1,5-diazabicyclo[5.4.0]undec-5-ene (DBU), and the ester protection is removed with trifluoroacetic acid to give 4. The amide side chain is removed by the usual PCl5/dimethylaniline sequence followed by reamidation with the appropriate acid chloride to give cefroxadine (5).
See also
References
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- ↑ <templatestyles src="Citation/styles.css"/>Template:Citation/make link, Bickel, Hans & Scartazzini, Riccardo, "Enolderivate [Enol derivatives]", published Script error: No such module "auto date formatter"., assigned to Ciba-Geigy AGScript error: No such module "Check for unknown parameters".
- ↑ R. Scartazzini, H. Bickel, U.S. patent 4073902 (1978 to Ciba-Geigy).
- ↑ R. B. Woodward and H. Bickel, U.S. patent 4147864 (1979); Chem. Abstr., 91, 74633J (1979).
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