181530-09-6Relevant articles and documents
NOVEL PREPARATION METHOD OF QUINOLINE N-OXIDE DERIVATIVE WITH AMIDE GROUP
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Paragraph 259; 260, (2015/11/09)
Provided are a preparation method of a quinoline N-oxide derivative with an amide group capable of easily introducing the amide group into the quinoline N-oxide derivative by simplified processes and mild reaction conditions, and a quinoline N-oxide derivative with an amide group prepared by using the same.
Regioselective introduction of heteroatoms at the C-8 position of quinoline N-oxides: Remote C-H activation using N-oxide as a stepping stone
Hwang, Heejun,Kim, Jinwoo,Jeong, Jisu,Chang, Sukbok
, p. 10770 - 10776 (2014/08/18)
Reported herein is the metal-catalyzed regioselective C-H functionalization of quinoline N-oxides at the 8-position: direct iodination and amidation were developed using rhodium and iridium catalytic systems, respectively. Mechanistic study of the amidation revealed that the unique regioselectivity is achieved through the smooth formation of N-oxide-chelated iridacycle and that an acid additive plays a key role in the rate-determining protodemetalation step. While this approach of remote C-H activation using N-oxide as a directing group could readily be applied to a wide range of heterocyclic substrates under mild conditions with high functional group tolerance, an efficient synthesis of zinquin ester (a fluorescent zinc indicator) was demonstrated.
Aqueous coordination chemistry of quinoline-based fluorescence probes for the biological chemistry of zinc
Fahrni, Christoph J.,O'Halloran, Thomas V.
, p. 11448 - 11458 (2007/10/03)
Metal-specific fluorescence probes are of increasing importance in understanding the neurobiology and general cell biology of zinc. Several quinoline-based compounds such as TSQ and zinquin have been employed to detect zinc in fluorescence microscopy experiments in vivo; however, the aqueous solution chemistry remains equivocal. In some cases, this family of probes is said to reveal labile pools of Zn(II) inside the cell, yet in other cases, these probes are suggested to remove Zn(II) from tightly bound sites in proteins. Since the binding modes, coordination numbers, and thermodynamics of zinc-zinquin interactions in aqueous solution have not been established, these proposals are difficult to distinguish. Here we show that, under physiological conditions, the various forms of zinquin bind Zn(II) with a high degree of cooperativity forming 2:1 complexes. Potentiometric, UV-visible, and fluorescence methods all yield an overall binding constant of log K = 13.5 under physiological conditions. To put this number in perspective with other Zn chelators and biological ligands, we compare the calculated so-called pM values (-log[Zn(II)]free) for a series of compounds with different stoichiometries under a typical condition. The pZn value for zinquin (9.3) is similar to that of EGTA (9.5) but much smaller than the value for carbonic anhydrase (12.4) or EDTA (14.3) and, thus, serves as a useful gauge for comparing zinc affinities. With respect to in vivo applications of zinquin, such as intracellular fluorescence microscopy studies, we find that the typical detection limit for free Zn(II) in aqueous solution is 4 pM, or 0.3 parts per trillion, at pH 7.2. These results have implications for the availability of zinc in various intracellular compartments.
The synthesis of zinquin ester and zinquin acid, zinc(II)-specific fluorescing agents for use in the study of biological zinc(II)
Mahadevan, Indumathy B.,Kimber, Marc C.,Lincoln, Stephen F.,Tiekink, Edward R.T.,Ward, A. David,Betts, W. Henry,Forbes, Ian J.,Zalewski, Peter D.
, p. 561 - 568 (2007/10/03)
The syntheses of Zinquin ester [ethyl [2-methyl-8-(p-tolylsulfonylamino)-6-quinolyloxy]acetate) and the corresponding acid, both of which are zinc(II)-specific fluorophores, are described. 6-Methoxy-2-methyl-8-(p-tolylsulfonylamino)quinoline (2) can be de
