Rearrangement of 3,3-Disubstituted 1-Aryl-4,5-dihydro-5-oxo-3<i>H</i>-1,2,4-triazolium Tetrafluoroborates; Part 1. A Versatile Synthesis of 1,5-Disubstituted 2-Aryl-1,2-dihydro-3<i>H</i>-1,2,4-triazol-3-one Tetrafluoroborates
作者:Hubert Gstach、Patrick Seil
DOI:10.1055/s-1990-27021
日期:——
α-(Arylazo)alkyl isocyanates 3 react with tetrafluoroboric acid to yield 3, 3-disubstituted 1-aryl-4,5-dihydro-5-oxo-3H-1,2,4-triazo-lium tetrafluoroborates 4. These compounds rearrange under mild conditions and in good yields to the tetrafluoroborates of 1,5 disubstituted 2-aryl-1,2-dihydro-3H-1,2, 4-triazol-3-ones 5. Our results show that the nature of the substituents determines their migratory aptitude for the rearrangement.
Autoxidation of hydrazones is a generally occurring reaction, leading mostly to the formation of α-azohydroperoxides. All structural kinds of hydrazones, having at least one hydrogen atom on nitrogen, are prone to autoxidation; however, there are marked differences in the rate of the reaction. Hydrazones of aliphatic ketones are 1−2 orders of magnitude more reactive than analogous derivatives of aromatic
One-pot synthesis of an indole-substituted 7,8-dicarba-nido-dodecahydroundecaborate(−1)
作者:W. Neumann、R. Frank、E. Hey-Hawkins
DOI:10.1039/c4dt03218g
日期:——
Carbaboranes are increasingly used as pharmacophores to replace phenyl substituents in established drug molecules. In contrast to traditional organic chemistry, elaborate procedures to introduce functionality frequently fail in the case of carbaboranes and their chemistry is often hampered by degradation of the cluster. Herein, the development of a one-pot synthesis of a water-soluble N-nido-dicarbaborato
Inhibition of Cytosolic Phospholipase A<sub>2</sub>α: Hit to Lead Optimization
作者:John C. McKew、Megan A. Foley、Paresh Thakker、Mark L. Behnke、Frank E. Lovering、Fuk-Wah Sum、Steve Tam、Kun Wu、Marina W. H. Shen、Wen Zhang、Mario Gonzalez、Shanghao Liu、Anu Mahadevan、Howard Sard、Soo Peang Khor、James D. Clark
DOI:10.1021/jm0507882
日期:2006.1.1
Compound I was previously reported to be a potent inhibitor of cPLA,(x in both artificial monomeric substrate and cell-based assays. However, I was inactive in whole blood assays previously used to characterize cyclooxygenase and lipoxygenase inhibitors. The IC(50) of 1 increased dramatically with cell number or lipid/detergent concentration. In an attempt to insert an electrophilic ketone between the indole and benzoic acid moieties, we discovered that increasing the distance between the two moieties gave a compound with activity in the GLU (7-hydroxycoumarinyl-gamma-linolenate) micelle assay, which contains lipid and detergent. Extensive structure-activity relationship work around this lead identified a potent pharmacophore for cPLA a inhibition. The IC(50)s between the GLU micelle and rat whole blood assays correlated highly. No correlation was found for other parameters, including lipophilicity or acidity of the required acid functionality. Compounds 25, 39, and 94 emerged as potent, selective inhibitors of cPLA(2)alpha and represent well-validated starting points for further optimization.
Ray, Partha S.; Hank, Richard F., Journal of Heterocyclic Chemistry, 1990, vol. 27, # 7, p. 2017 - 2020