zoxazolamine zoxazolamine zoxazolamine (inn, usan, ban) (brand name contrazole, deflexol, flexin, miazol, uri-boi, zoxamine, zoxine) is a muscle relaxant that is no longer marketed. it was synthesized in 1953 and introduced clinically in 1955 but was withdrawn due to hepatotoxicity. one of its active metabolites, chlorzoxazone, was found to show less toxicity, and was subsequently marketed in place of zoxazolamine. these drugs activate ikca channels. zoxazolamineclinical dataother namesmcn-485routes ofadministrationoralidentifiers iupac name 5-chloro-1,3-benzoxazol-2-amine cas number61-80-3pubchem cid6103chemspider5878unii9dow362q29keggc13841chebichebi:35053chemblchembl472566chemical and physical dataformulac7h5cln2omolar mass168.58 g·mol−13d model (jsmol)interactive image smiles c1=cc2=c(c=c1cl)n=c(o2)n inchi inchi=inchi=1s/c7h5cln2o/c8-4-1-2-6-5(3-4)10-7(9)11-6/h1-3h,(h2,9,10)key:ygcodsqduuukiv-uhfffaoysa-n