与之前报道的在 C-5 中心功能化咪唑并[1,2- a ]吡啶的自由基途径相比,指导基团方法很少见。在此,我们展示了一种铑( III )催化的高效和区域选择性策略,用于使用N-甲氧基酰胺作为定向基团对咪唑并[1,2- a ]吡啶进行定向C-5官能化。该方法有利于定向芳基化,无需预功能化。它还允许进行克级合成和后功能化。
Microwave Assisted Synthesis of Disubstituted Imidazo[1,2-a]pyridine-3-carboxylic Acid Esters
摘要:
A novel and efficient synthetic method leveraging microwave-assisted organic synthesis (MAOS) to prepare disubstituted imidazo[1,2-a]pyridine-3-carboxylic acid esters (IPCEs) (3a-z), the key intermediates for a class of novel anti-tuberculosis agents, is reported. Under microwave heating at 120 degrees C for 20 or 30 min, the condensations of 2-aminopyridines (1a-k) and ethyl 2-halogenated acetoacetates (2a-d) were conveniently performed in ethanol with acceptable yields.
Photocatalytic regeneration of brominating agent in the visible light-mediated synthesis of imidazo[1,2-<i>a</i>]pyridines
作者:Irwan Iskandar Roslan、Kian-Hong Ng、Stephan Jaenicke、Gaik-Khuan Chuah
DOI:10.1039/c9cy00141g
日期:——
supporting evidence of a reductive quenching pathway. The avoidance of stoichiometric excess of the halogen or peroxide oxidants for halide regeneration makes this protocol an environmentally-friendly synthesis with low E-factor.
在可见光介导的光催化下,将1,3-二羰基与2-氨基吡啶偶联可以得到各种各样的咪唑并[1,2- a ]吡啶。使用便宜的和可商购的荧光素染料赤藓红B作为光氧化还原催化剂,KBr作为卤化剂进行原位溴化。该方案的特征在于使用催化量的卤化剂,该卤化剂由光催化剂在可见光照射下再生。循环伏安法研究提供了还原性淬灭途径的支持证据。避免化学计量过量的卤素或过氧化物氧化剂用于卤化物的再生,使该方案成为具有低E因子的环境友好的合成方法。
Design, synthesis and biological activity of N-(2-phenoxy)ethyl imidazo[1,2-a]pyridine-3-carboxamides as new antitubercular agents
A series of N-(2-phenoxy)ethyl imidazo[1,2-a]pyridine-3-carboxamides (IPAs), based on the structure of WZY02 discovered in our lab, were designed and synthesized as new anti-TB agents. Results reveal that many of them exhibit excellent in vitro inhibitory activity with low nanomolar MIC values against both drug-sensitive MTB strain H37Rv and drug-resistant clinical isolates. Compounds 15b and 15d display
根据在我们实验室中发现的WZY02的结构,设计并合成了一系列N-(2-苯氧基)乙基咪唑并[1,2 - a ]吡啶-3-甲酰胺(IPAs),作为新型抗结核药物。结果表明,它们中的许多对药物敏感性MTB菌株H37Rv和耐药性临床分离株均表现出优异的体外抑制活性,且纳摩尔摩尔MIC值低。化合物15b和15d显示出良好的安全性和药代动力学特征,表明它们有望成为未来抗结核药物发现的先导化合物。
Advancement of Imidazo[1,2-<i>a</i>]pyridines with Improved Pharmacokinetics and nM Activity vs. <i>Mycobacterium tuberculosis</i>
作者:Garrett C. Moraski、Lowell D. Markley、Jeffrey Cramer、Philip A. Hipskind、Helena Boshoff、Mai A. Bailey、Torey Alling、Juliane Ollinger、Tanya Parish、Marvin J. Miller
DOI:10.1021/ml400088y
日期:2013.7.11
A set of 14 imidazo[1,2-a]pyridine-3-carboxamides was synthesized and screened against Mycobacterium tuberculosis H(37)Rv. The minimum inhibitory concentrations of 12 of these agents were <= 1 mu M against replicating bacteria and 5 compounds (9, 12, 16, 17, and 18) had MIC values <= 0.006 mu M. Compounds 13 and 18 were screened against a panel of MDR and XDR drug resistant clinical Mtb strains with the potency of 18 surpassing that of clinical candidate PA-824 by nearly 10-fold. The in vivo pharmacokinetics of compounds 13 and 18 were evaluated in male mice by oral (PO) and intravenous (IV) routes. These results indicate that readily synthesized imidazo[1,2-a]pyridine-3-carboxamides are an exciting new class of potent, selective anti-TB agents that merit additional development opportunities.