estrone benzoate estrone benzoate estrone benzoate, or estrone 3-benzoate, is a synthetic estrogen and estrogen ester – specifically, the c3 benzoate ester of estrone – which was first reported in 1932 and was never marketed. it led to the development in 1933 of the more active estradiol benzoate, the first estradiol ester to be introduced for medical use. estrone benzoateclinical dataother namesketohydroxyestrin benzoate; estra-1,3,5(10)-trien-3-ol-17-one 3-benzoateroutes ofadministrationintramuscular injectiondrug classestrogen; estrogen esteridentifiers iupac name phenanthren-3-yl] benzoate cas number2393-53-5pubchem cid15818351chemspider18553608uniio636lyl5w8chemblchembl1628207comptox dashboard (epa)dtxsid00946752 chemical and physical dataformulac25h26o3molar mass374.480 g·mol−13d model (jsmol)interactive image smiles c12cc3(1ccc2=o)ccc4=c3c=cc(=c4)oc(=o)c5=cc=cc=c5 inchi inchi=1s/c25h26o3/c1-25-14-13-20-19-10-8-18(28-24(27)16-5-3-2-4-6-16)15-17(19)7-9-21(20)22(25)11-12-23(25)26/h2-6,8,10,15,20-22h,7,9,11-14h2,1h3/t20-,21-,22+,25+/m1/s1key:hkukrslievxdms-apdhkmkfsa-n