1-Aryl-3-(4-pyridine-2-ylpiperazin-1-yl)propan-1-one Oximes as Potent Dopamine D4 Receptor Agonists for the Treatment of Erectile Dysfunction
摘要:
A new series of dopamine D-4 receptor agonists, 1-aryl-3-(4-pyridinepiperazin-1-yl) propanone oximes, was designed through the modification of known dopamine D4 receptor agonist PD 168077. Replacement of the amide group with a methylene-oxime moiety produced compounds with improved stability and efficacy. Structure-activity relationsips (SAR) of the aromatic ring linked to the N-4-piperazine ring confirmed the superiority of 2-pyridine as a core for D4 agonist activity. A two-methylene linker between the oxime group and the N-1-piperazine ring displayed the best profile. New dopamine D4 receptor agonists, exemplified by (E)-1-(4-chlorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl) propan-1-one O-methyloxime (59a) and (E)-1-(3-chloro- 4-fluorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl) propan-1-one O-methyloxime (64a), exhibited favorable pharmacokinetic profiles and showed oral bioavailability in rat and dog. Subsequent evaluation of 59a in the rat penile erection model revealed in vivo activity, comparable in efficacy to apomorphine. Our results suggest that the oximes provide a novel structural linker for 4-arylpiperazine-based D4 agonists, possessing leadlike quality and with potential to develop a new class of potent and selective dopamine D4 receptor agonists.
Design, synthesis and biological evaluation of novel ring-opened cromakalim analogues with relaxant effects on vascular and respiratory smooth muscles and as stimulators of elastin synthesis
vascular smooth muscle cells showed a strong stimulating effect on elastin synthesis, especially compound B16, which was more active at 20 μM than diazoxide, a reference ATP-sensitive potassium channel activator. Taken together, our results show that the N-methylation of the sulfonylurea moieties of ring-opened cromakalim analogues led to new compounds blocking calcium-gated channels, which had a major
A variety of fluorescent 5-aryl-2,3-dicyanofurans were prepared by the treatment of electron-rich aryl ketones with DDQ. The presence of an alkoxy substituent on the benzene ring in the substrates was essential for an efficient cyclization to occur. This novel approach allows the metal-free construction of furan rings from simple aryl ketones.
2-(methylthio)-4H-chromen-4-ones by intramolecular cyclization of easily accessible 1-(2-benzyloxy-aryl)-3,3-bis-methylsulfanyl-propenones. The synthesized chromen-4-ones turn out to be a key precursor for various kinds of chemical reactions. Mechanistically, we observed that iodine-mediated intramolecular cyclization of ketene dithioacetal proceeded through a radical pathway. 3-Halo-2-(methylthio)-4H-chromen-4-ones
开发了一种有效的碘介导方法,用于通过容易获得的 1-(2-苄氧基-芳基)-3,3-双-甲基硫烷基的分子内环化合成功能化的 2-(甲硫基)-4 H-色烯-4-酮-丙烯酮。合成的 chromen-4-ones 是各种化学反应的关键前体。从机制上讲,我们观察到碘介导的二硫代乙缩醛分子内环化是通过自由基途径进行的。3-Halo-2-(methylthio)-4 H -chromen-4-ones 是通过各种两锅或一锅卤化方法实现的。
Synthesis of Spirofurooxindoles via Phenyliodine(III) Bis(trifluoroacetate) (PIFA)-Mediated Cascade Oxidative C−O and C−C Bond Formation
Upon treatment with solely a hypervalent iodine reagent of phenyliodine(III) bis(trifluoroacetate) (PIFA), 3‐(2‐hydroxyphenyl)‐3‐oxo‐N‐phenyl propanamides and a series of its derivatives were conveniently converted to a class of undocumented spirofurooxindoles under mild conditions. Control experiments provided evidence that this spirocyclization process encompassed a cascade oxidative reactions involving