cefroxadine cefroxadine 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. cefroxadineclinical dataahfs/drugs.cominternational drug namesroutes ofadministrationoralatc codej01db11 (who) legal statuslegal status in general: ℞ (prescription only) pharmacokinetic dataelimination half-life~1 hourexcretionrenalidentifiers iupac name (6r,7r)-7--3-methoxy-8-oxo-5-thia-1-azabicyclooctane-2-carboxylic acid cas number51762-05-1pubchem cid443991chemspider4447587uniib908c4mv2rkeggd01528chemblchembl2104150comptox dashboard (epa)dtxsid1022768 echa infocard100.052.157 chemical and physical dataformulac16h19n3o5smolar mass365.40 g·mol−13d model (jsmol)interactive image smiles o=c2n1/c(=c(/oc)cs12nc(=o)(c/3=c/c\c=c/c\3)n)c(=o)o it is available in italy. 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). synthesis of cefroxadine 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-diazabicycloundec-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).