Rational Design of 5-Phenyl-3-isoxazolecarboxylic Acid Ethyl Esters as Growth Inhibitors of Mycobacterium tuberculosis. A Potent and Selective Series for Further Drug Development
摘要:
New antituberculosis (anti-TB) drugs are urgently needed to shorten the 6-12 month treatment regimen and especially to battle drug-resistant Mycobacterium tuberculosis (Mtb) strains. In this study, we have continued our efforts to develop isoxazole-based anti-TB compounds by applying rational drug design approach. The biological activity and the structure-activity relationships (SAR) for a designed series of 5-phenyl-3-isoxazolecarboxylic acid ethyl ester derived anti-TB compounds were investigated. Several compounds were found to exhibit nanomolar activity against the replicating bacteria (R-TB) and low micromolar activity against the nonreplicating bacteria (NRP-TB). The series showed excellent selectivity toward Mtb, and in general, no cytotoxicity was observed in Vero cells (IC50 > 128 mu M). Notably, selected compounds also retained their activity against isoniazid (INH), rifampin (RMP), and streptomycin (SM) resistant Mtb strains. Hence, benzyloxy, benzylamino, and phenoxy derivatives of 5-phenyl-3-isoxazolecarboxylic acid ethyl esters represent a highly potent, selective, and versatile series of anti-TB compounds and as Such present attractive lead compounds for further TB drug development.
Oxidize Amines to Nitrile Oxides: One Type of Amine Oxidation and Its Application to Directly Construct Isoxazoles and Isoxazolines
作者:Xiao-Wei Zhang、Xiao-Lin He、Nan Yan、Hong-Xing Zheng、Xiang-Guo Hu
DOI:10.1021/acs.joc.0c02281
日期:2020.12.4
A facile oxidative heterocyclization of commercially available amines and tert-butyl nitrite with alkynes or alkenes leading to isoxazoles or isoxazolines is described. The unprecedented strategy of the oxidation of an amine directly to a nitrile oxide was used in this cyclization process. This reaction is highly efficient, regiospecific, operationally simple, mild, and tolerant of a variety of functional
Cu-Catalyzed Synthesis of Fluoroalkylated Isoxazoles from Commercially Available Amines and Alkynes
作者:Xiao-Wei Zhang、Wen-Li Hu、Suo Chen、Xiang-Guo Hu
DOI:10.1021/acs.orglett.7b04028
日期:2018.2.2
A one-potprotocol for the construction of fluoroalkylated isoxazoles directly from commercially available amines and alkynes is described. The reaction is scalable, operationally simple, regioselective, mild, and tolerant of a broad range of functional groups. As such, it could be viewed as a “click synthesis” of fluoroalkylated isoxazoles. Preliminary mechanistic investigations reveal that the transformation
描述了一种直接从市售胺和炔烃构建氟代烷基化异恶唑的一锅法操作规程。该反应是可扩展的,操作简单的,区域选择性的,温和的,并且耐受多种官能团。因此,可以将其视为氟代烷基化异恶唑的“点击合成”。初步的机械研究表明,该转化涉及涉及R f CHN 2的空前的Cu催化级联序列。