The synthesis of non-steroidal estrogen receptor binding compounds labeled with 80mBr

Estrogen receptor (ER) binding radiopharmaceuticals have potential for use in the diagnosis and treatment of cancers of the female reproductive system. Two triphenylethylene derivatives based on the structure of hydroxytamoxifen 4, a high ER binding metabolite of tamoxifen 5, have been prepared: 1-(4-dimethylaminoethoxy)phenyl]-1-(4-hydroxy)phenyl-2-bromo-2-phenyl ethylene 2 and 1,1-bis (p-hydroxyphenyl)-2-bromo-2-phenylethylene 3. Both 2 and 3 bind strongly to the ER. Compound 3 has been labeled in modest yield by direct bromination with 80mBr, which was produced by the 83Kr (d,n alpha) reaction. Radiolabeled 22, a dimethoxy precursor of 3, has been prepared in yields ranging between 40 and 60% by a bromination destannylation reaction.