Synthesis of fluorine-18 labeled 21-fluoroprogesterone

21-Fluoroprogesterone has been synthesized by the nucleophilic displacement of the mesyl group of the 21-hydroxypregn-4-ene-3,20-dione 21-methanesulfonate by fluoride ion, as formed from the solvolysis of potassium fluoride in acetonitrile, using 18-Crown-6 as the catalyst. In a similar manner, the synthesis of 21-fluoroprogesterone labeled with fluorine-18 has been accomplished, producing approximately 800 muCi of product from 6 mCi of K18F in one hour. This demonstrates that 18F labeled molecules of potential values as readiopharmaceuticals can be prepared rapidly in sufficient yield to allow animal investigation.