RT Journal Article SR Electronic T1 Fluorinated androgens and progestins: molecular probes for androgen and progesterone receptors with potential use in positron emission tomography. JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 391 OP 403 VO 32 IS 3 A1 S J Brandes A1 J A Katzenellenbogen YR 1987 UL http://molpharm.aspetjournals.org/content/32/3/391.abstract AB In order to develop imaging agents for receptor-positive tumors of the breast and prostate, we have investigated the binding affinity of several fluorine-substituted steroids in the testosterone and nortestosterone series for the androgen receptor and the progesterone receptor. The 6 alpha- and 11 beta-fluoro-, and 16 alpha-fluoroalkyl-substituted steroids were prepared by an olefin bromofluorination reaction followed by dehydrobromination or reductive debromination. The 17 alpha-fluoromethyl derivatives were prepared by fluoride ion attack on the 17-spiroepoxide or 17-spiro sulfate and the 17 alpha-fluoropropynyl derivative, by reaction of a propargyl alcohol precursor with diethylaminosulfur trifluoride. Of the compounds synthesized, 17 alpha-(3-fluoro-I-propynyl)nortestosterone was found to possess the highest binding affinity and selectivity for the progesterone receptor, and 11 beta-fluoronordihydrotestosterone had the greatest affinity for the androgen receptor. Both receptor systems seem to tolerate reasonably well the substitution of fluorine for hydrogen.