Acta Pharm. 56 (2006) 203-218
[ Full paper in PDF ]Condensation of 3ß-hydroxy-16-[(4-chlorophenyl)methylene]androst-5-en-17-one (1) with hydrazine hydrate in acetic acid afforded N-acetyl pyrazoline derivative 2, while, condensation of 1 with semicarbazide afforded compound 3. Also, compound 1 was treated with hydrazine hydrate in absolute methanol or ethanol to afford the corresponding alpha-methoxy (4) and alpha-ethoxy (5) derivatives, which were cyclized with etherated boron trifluoride to the pyrazoline derivative 6. The latter could be prepared directly by refluxing 1 with hydrazine hydrate in dioxane. Oxidation of compound 6 with Oppenour or Moffat oxidizing agents yielded 3-oxo-derivatives 7 and 8, respectively. On the other hand, condensation of compound 1 with substituted hydrazines, gave the corresponding 3beta-hydroxyandrostenopyrazolines 9a,b, which were oxidized using the Moffat method give 3-oxo-androstenopyrazolines 10a,b, which were condensed with ethylene triphenyl-phosphorane in DMSO to yield 3-ethylene androstenopyrazolines 11a,b. Dehydrogenation of 9a,b with Wettestein oxidation afforded delta4,6-diene-3-one analogues 12a,b, which were treated with chloranil to yield delta4,6,8(14)-triene-3-one analogues 13a,b. Oppenour oxidation of 9a,b afforded delta4-ene-3-one analogues 14a,b, which were treated with dichlorodicyanoquinone (DDQ) in dioxane to give delta1,4,6-triene-3-one analogues 15a,b. Pharmacological screening showed that many of these compounds inhibit 5alpha-reductase activity.
Keywords: testosterone, pyrazolines, Moffat oxidation, 5alpha-reductase inhibitor, pharmacological screening