5-Phenyl substituted 1-methyl-2-pyridones and 4'-substituted biphenyl-4-carboxylic acids. synthesis and evaluation as inhibitors of steroid-5alpha-reductase type 1 and 2.
The synthesis of a series of 5-phenyl substituted 1-methyl-2-pyridones (I) and 4'-substituted biphenyl-4-carboxylic acids (II) as novel A-C ring steroidomimetic inhibitors of 5alpha-reductase (5alphaR) is described. Compounds 1-4 (I) were synthesized by palladium catalyzed cross coupling (Ishikura) reaction between diethyl(3-pyridyl)borane and aryl halides (1b-4b) followed by alpha-oxidation with sodium ferrocyanate of the 1-methyl-pyridinium salt. Inhibitors II (5-18) were obtained either by two successive Friedel-Crafts acylations from biphenyl (5a-10a) followed by saponification to yield the corresponding carboxylic acids (5-10) or by Suzuki cross coupling reaction to give the 4'-substituted biphenyl-4-carbaldehydes 11a-18a. The latter compounds were subjected to a Lindgren oxidation to yield compounds 11-18. The compounds were tested for inhibitory activity toward human and rat 5alphaR1 and 2. The test compounds inhibited 5alphaR, showing a broad range of inhibitory potencies. The best compound in series I was the N-(dicyclohexyl)-4-(1,2-dihydro-1-methyl-2-oxopyrid-5-yl)benzamide 4 exhibiting an IC(50) value for the human type 2 enzyme of 10 microM. In series II, the most active compound toward human type 2 isozyme was the 4'-(dicyclohexyl)acetyl-4-biphenyl carboxylic acid (10; IC(50)=220nM). Both series showed only marginal activity toward the human type 1 isozyme. In conclusion, the biphenyl carboxylic acids (II) are more appropriate for 5alphaR inhibition than the 5-phenyl-1-methyl-2-pyridones (I). Especially the 4'-carbonyl compounds 5-10 represent new lead structures for the development of novel human type 2 inhibitors.
Picard
Franck
F
8.5 Pharmaceutical and Medicinal Chemistry, Saarland University, PO Box 15 11 50, D-66041, Saarbrücken, Germany.
Schulz
Tobias
T
Hartmann
Rolf W
RW
D058891:5-alpha Reductase Inhibitors; D000818:Animals; D002264:Carboxylic Acids / Q000737:chemistry; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D008297:Male; D011467:Prostate / Q000187:drug effects / Q000201:enzymology; D051381:Rats
D058891:5-alpha Reductase Inhibitors; D002264:Carboxylic Acids; D004791:Enzyme Inhibitors; D007527:Isoenzymes