estramustine estramustine estramustine (inn, usan, ban) is an estrogen and cytostatic antineoplastic agent which was never marketed. it is an estrogen ester – specifically, the c3 normustine ester of estradiol – and acts in part as a prodrug of estradiol in the body. estramustine phosphate, the c17β phosphate ester of estramustine and a prodrug of estramustine, estromustine, estradiol, and estrone, is marketed and used in the treatment of prostate cancer. this article is about a non-clinically used compound. for the pharmaceutical drug, see estramustine phosphate. estramustineclinical datatrade namesemcyt, estracytother namesem; eam; leo 275; ro 21-8837; estradiol 3-(bis(2-chloroethyl)carbamate) ester; estra-1,3,5(10)-triene-3,17β-diol 3-(bis(2-chloroethyl)carbamate) esterdrug classchemotherapeutic agent; estrogen; estrogen esteratc codel01xx11 (who) identifiers iupac name phenanthren-3-yl] n,n-bis(2-chloroethyl)carbamate cas number2998-57-4 ypubchem cid259331chemspider227635 yunii35lt29625akeggd04066 ychebichebi:4868 ychemblchembl1575 ycomptox dashboard (epa)dtxsid8046458 echa infocard100.019.161 chemical and physical dataformulac23h31cl2no3molar mass440.41 g·mol−13d model (jsmol)interactive image smiles c12cc3(1cc2o)ccc4=c3c=cc(=c4)oc(=o)n(cccl)cccl inchi inchi=1s/c23h31cl2no3/c1-23-9-8-18-17-5-3-16(29-22(28)26(12-10-24)13-11-25)14-15(17)2-4-19(18)20(23)6-7-21(23)27/h3,5,14,18-21,27h,2,4,6-13h2,1h3/t18-,19-,20+,21+,23+/m1/s1 ykey:frpjxpjmrwbbih-rbrwejtlsa-n y