855-55-0Relevant articles and documents
Kinetics of Electrophilic Fluorination of Steroids and Epimerisation of Fluorosteroids
Rozatian, Neshat,Harsanyi, Antal,Murray, Ben J.,Hampton, Alexander S.,Chin, Emily J.,Cook, Alexander S.,Hodgson, David R. W.,Sandford, Graham
, p. 12027 - 12035 (2020/08/28)
Fluorinated steroids, which are synthesised by electrophilic fluorination, form a significant proportion of marketed pharmaceuticals. To gain quantitative information on fluorination at the 6-position of steroids, kinetics studies were conducted on enol ester derivatives of progesterone, testosterone, cholestenone and hydrocortisone with a series of electrophilic N?F reagents. The stereoselectivities of fluorination reactions of progesterone enol acetate and the kinetic effects of additives, including methanol and water, were investigated. The kinetics of epimerisation of 6β-fluoroprogesterone to the more pharmacologically active 6α-fluoroprogesterone isomer in HCl/acetic acid solutions are detailed.
Synthesis of C-6 fluoroandrogens: Evaluation of ligands for tumor receptor imaging
Choe, Yearn Seong,Katzenellenbogen, John A.
, p. 414 - 422 (2007/10/02)
Seven androgens, substituted with fluorine at C-6, were prepared as potential imaging agents for androgen receptor-positive prostate tumors and were evaluated in vitro in terms of their lipophilicity and their relative binding affinities (RBA, relative to R1881 = 100) for the androgen receptor and for sex steroid binding protein.Introduction of a fluorine atom into the C-6 position of an androgen generally decreases binding affinity to the androgen receptor, except in the two cases: 6α-fluoro-19-nor-testosterone RBA = 41.6 versus 30.6 for the unsubstituted steroid) and 6α-fluorotestosterone (RBA = 8.9 versus 6.6).Receptor binding of the C-6 fluoro-androgens is also stereospecific, showing higher binding affinities for the α-epimers compared to the corresponding β-epimers (4:1 - 15:1).Binding affinity to sex steroid binding protein is the lowest with 19-nor-testosterone, which is also the least lipophilic androgen studied.Based on the binding properties of compounds in this series, 6α-fluoro-19-nor-testosterone appears to have the most promise as a tumor imaging agent. - Keywords: C-6-fluoroandrogens; fluorine substitution; relative binding affinity; 6α- and 6β-epimers; log Po/w; prostate tumors
CONTROLLED SELECTIVE FLUORINATION WITH N-FLUOROPYRIDINIUM SALT SYSTEM
Tomizawa, Ginjiro,Umemoto, Teruo
, p. 205 (2007/10/02)
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