Synthesis and Structure−activity Relationships of Antitubercular 2-Nitroimidazooxazines Bearing Heterocyclic Side Chains
摘要:
Recently described biphenyl analogues Of the antituberculosis drug PA-824 displayed improved potencies against M. tuberculosis but were poorly soluble. Heterobiaryl analogues of these, in which the first phenyl ring was replaced with various 5-membered ring heterocycles, were prepared with the aim of identifying potent new candidates with improved aqueous solubility. The compounds were constructed by coupling the chiral 2-nitroimidazooxazine alcohol with various halomethyl-substituted arylheterocycles, by cycloadditions to a propargyl ether derivative of this alcohol, or by Suzuki couplings on haloheterocyclic methyl ether derivatives. The arylheterocyclic compounds were all more hydrophilic than their corresponding biphenyl analogues, and several showed solubility improvements. 1-Methylpyrazole, 1,3-linked-pyrazole, 2,4-linked-triazole, and tetrazole analogues had 3- to 7-fold higher MIC potencies against replicating M. tb than predicted by their lipophilicities. Two pyrazole analogues were >10-fold more efficacious than the parent drug in a mouse model of acute M. tb infection, and one displayed a 2-fold higher solubility.
One-flask synthesis of 1,3,5-trisubstituted 1,2,4-triazoles from nitriles and hydrazonoyl chlorides via 1,3-dipolar cycloaddition.
一瓶法合成1,3,5-三取代-1,2,4-三唑,从腈和叠氮酰氯通过1,3-偶极环加成。
Synthesis of novel pyrazoles incorporating a phenothiazine moiety: unambiguous structural characterization of the regioselectivity in the 1,3-dipolar cycloaddition reaction using 2D HMBC NMR spectroscopy
作者:Ahmed E.M. Mekky、Tamer S. Saleh、Abdullah S. Al-Bogami
DOI:10.1016/j.tet.2013.06.028
日期:2013.8
An efficient and attractive regioselective synthesis of a series of novel pyrazoles containing a phenothiazine moiety was achieved utilizing microwave irradiation. Unambiguous structural assignment of the obtained regioisomers was determined utilizing 2D HMBC NMR techniques as a valuable tool.
therapy. CXCR2 antagonists could block CXCLs/CXCR2 axis, and are widely used in regulating immune cell migration, tumor metastasis, apoptosis and angiogenesis. Herein, two series of new CXCR2 small-molecule inhibitors, including 1,2,4-triazol-3-one derivatives 1–11 and pyridazinone derivatives 12–22 were designed and synthesized based on the proof-to-concept. The pyridazinone derivative 18 exhibited
Microwave-assisted Regioselective Synthesis of Novel Bis(azoles) and Bis(azoloazines)
作者:Abdullah S. Al-Bogami、Ahmed E. M. Mekky
DOI:10.1002/jhet.2462
日期:2016.9
We introduce efficient regioselectivesynthesis of a series of novel bis(pyrazoles) and bis(isoxazoles) via 1,3‐dipolar cycloaddition reaction under microwave irradiation. Unequivocal structural assignment of the obtained regioisomers was determined utilizing 1H‐13C HMBC NMR techniques as a valuable tool. A comparative study of the aforementioned reactions was carried out under conventional method
通过微波辐射下的1,3-偶极环加成反应,我们介绍了有效的区域选择性合成一系列新型双(吡唑)和双(异恶唑)的方法。使用1 H- 13 C HMBC NMR技术作为有价值的工具确定了获得的区域异构体的明确结构分配。在常规方法以及微波辐射条件下进行了上述反应的比较研究。
Design, synthesis, and photophysics of bi- and tricyclic fused pyrazolines
作者:Alexandra V. Popova、Ali Kanaa、Vladislava S. Vavilova、Maria A. Mironova、Pavel A. Slepukhin、Enrico Benassi、Nataliya P. Belskaya
DOI:10.1039/d0nj06287a
日期:——
Three series of bi- and tricyclicfunctionalized new pyrazoline fluorophores have been synthesized for investigation of their photophysicalproperties. Spectral studies indicated significant absorption and emission properties. The quantum yields reached 93% and Stokes shifts increased up to 148 nm. The compounds exhibited positive solvato(fluoro)chromism. Fluorescence was sensitive to both structural
合成了三个系列的双环和三环功能化的新型吡唑啉荧光团,以研究其光物理性质。光谱研究表明明显的吸收和发射性质。量子产率达到93%,斯托克斯位移增加到148 nm。该化合物表现出正溶剂化(氟)色度。荧光对结构变化和微环境都敏感,特别是对质子溶剂,如EtOH,n -BuOH和DMSO / H 2敏感O的混合物,与乙二醇。实验结果得到了量子力学计算的支持。取代基的电子性质及其空间效应的修饰可以改变分子内电荷转移(ICT)的性质和方向。这些发现为开发具有可调光物理性质的新型稠合吡唑啉提供了宝贵的见识。吡唑啉表现出高强度的固态发射,使其适合用于光子学。活性官能团可用于结合吡唑啉和天然化合物,药物和诊断分子,以用于生物系统和药物中。