norethisterone acetate oxime norethisterone acetate oxime norethisterone acetate oxime (developmental code names orf-5263, so-36), or norethindrone acetate oxime, is a steroidal progestin of the 19-nortestosterone group which was developed as a postcoital contraceptive but was never marketed. it is the c3 oxime and c17β-acetate ester of norethisterone. norethisterone acetate oximeclinical dataother namesnorethindrone acetate oxime; orf-5263; so-36; norethisterone-3-oxime acetate; 17α-ethynyl-19-nortestosterone 3-oxime 17β-acetateroutes ofadministrationby mouthdrug classprogestogen; progestogen esteridentifiers iupac name (1s,2r,5e,10r,11s,14r,15s)-14-ethynyl-5-(hydroxyimino)-15-methyltetracycloheptadec-6-en-14-yl acetate cas number20799-24-0pubchem cid91758682uniivfk4d40pmqchemical and physical dataformulac22h29no3molar mass355.478 g·mol−13d model (jsmol)interactive image smiles cc(=o)o1(cc21(cc32ccc4=c/c(=n/o)/cc34)c)c#c inchi inchi=1s/c22h29no3/c1-4-22(26-14(2)24)12-10-20-19-7-5-15-13-16(23-25)6-8-17(15)18(19)9-11-21(20,22)3/h1,13,17-20,25h,5-12h2,2-3h3/b23-16+/t17-,18+,19+,20-,21-,22-/m0/s1key:sctdpgxgnwefnf-lqrgbyobsa-n