Phosphodiesterase inhibitors. Part 4: Design, synthesis and structure-activity relationships of dual PDE3/4-inhibitory fused bicyclic heteroaromatic-4,4-dimethylpyrazolones
作者:Koji Ochiai、Satoshi Takita、Akihiko Kojima、Tomohiko Eiraku、Naoki Ando、Kazuhiko Iwase、Tetsuya Kishi、Akira Ohinata、Yuichi Yageta、Tokutaro Yasue、David R. Adams、Yasushi Kohno
DOI:10.1016/j.bmcl.2012.07.088
日期:2012.9
(-)-6-(7-Methoxy-2-trifluoromethylpyrazolo[1,5-a]pyridin-4-yl)-5-methyl-4,5-dihydro-3-(2H)-pyridazinone (KCA-1490) is a dual PDE3/4 inhibitor that exhibits potent combined bronchodilatory and anti-inflammatory activity. Here we show that a 4,4-dimethylpyrazolone subunit serves as an effective surrogate for the 5-methyl-4,5-dihydropyridazin-3(2H)-one ring of KCA-1490 whilst lacking a stereogenic centre. The 2- and 7-substituents in the pyrazolo[1,5-a] pyridine subunit markedly influence the PDE-inhibitory profile and can be adjusted to afford either potent PDE4-selective inhibitors or dual PDE3/4 inhibitors. A survey of bicyclic heteroaromatic replacements for the pyrazolo[1,5-a] pyridine allowed further refinement of the inhibitory profile and identified 3-(8-methoxy-2-(trifluoromethyl) imidazo [1,2-a]pyridin-5-yl)-4,4-dimethyl-1H-pyrazol-5(4H)-one as an orally active, achiral KCA-1490 analog with well-balanced dual PDE3/4-inhibitory activity. (C) 2012 Elsevier Ltd. All rights reserved.
(-)-6-(7-甲氧基-2-三氟甲基吡razolo[1,5-a]吡啶-4-基)-5-甲基-4,5-二氢-3-(2H)-吡啶嗪酮(KCA-1490)是一种双重PDE3/4抑制剂,表现出强大的联合支气管扩张和抗炎活性。在这里,我们展示了一个4,4-二甲基吡咯酮亚单元可以作为KCA-1490中5-甲基-4,5-二氢吡啶嗪-3(2H)-酮环的有效替代,同时缺乏一个手性中心。吡razolo[1,5-a]吡啶亚单元中的2-和7-取代基对PDE抑制活性谱有显著影响,并且可以进行调整,以获得效力较强的PDE4选择性抑制剂或双重PDE3/4抑制剂。对吡razolo[1,5-a]吡啶的双环杂环芳香族替代物的调查进一步优化了抑制活性,并确定了3-(8-甲氧基-2-(三氟甲基)咪唑并[1,2-a]吡啶-5-基)-4,4-二甲基-1H-吡咯-5(4H)-酮作为KCA-1490的一种活性良好的非手性、具有双重PDE3/4抑制活性均衡的口服活性类似物。(C) 2012 Elsevier Ltd. 保留所有权利。