betamethasone acetate betamethasone acetate betamethasone acetate is a synthetic glucocorticoid corticosteroid and a corticosteroid ester. it is the 21-acetate ester of betamethasone. betamethasone acetateclinical datadrug classcorticosteroid; glucocorticoididentifiers iupac name (11,16β)-9-fluoro-11,17-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-21-yl acetate cas number987-24-6chemspider392014uniiti05ao53l7comptox dashboard (epa)dtxsid8022668 echa infocard100.012.344 chemical and physical dataformulac24h31fo6molar mass434.504 g·mol−13d model (jsmol)interactive image smiles c1c23ccc4=cc(=o)c=c4(3((c2(1(c(=o)coc(=o)c)o)c)o)f)c inchi inchi=1s/c24h31fo6/c1-13-9-18-17-6-5-15-10-16(27)7-8-21(15,3)23(17,25)19(28)11-22(18,4)24(13,30)20(29)12-31-14(2)26/h7-8,10,13,17-19,28,30h,5-6,9,11-12h2,1-4h3/t13-,17-,18-,19-,21-,22-,23-,24-/m0/s1key:akujbenlrboftd-qzixmdiesa-n