612-58-8Relevant articles and documents
Potent mutagenic potential of 4-methylquinoline: Metabolic and mechanistic considerations
Saeki, Ken-Ichi,Takahashi, Kazuhiko,Kawazoe, Yutaka
, p. 541 - 546 (1996)
4-Methylquinoline (4-MeQ) showed an extraordinarily potent mutagenicity when compared to quinolone and isomeric methylquinolines. The major metabolite of 4-MeQ was 4- hydroxymethylquinoline, which was not mutagenic under the assay condition employed. Deuteration of the methyl group of 4-MeQ resulted in a decrease in the amount of the hydroxymethyl metabolic and an increase in mutagenicity, indicating that hydroxylation of the substituent methyl group is a detoxication process. A 3-chloro derivative of 4-MeQ was proven to be non-mutagenic. 4-Ethyl- quinoline, as well as 4-hydroxymethylquinoline, was much less mutagenic than 4-MeQ. Taking account of the structure-mutagenicity relationship, a possible mechanism is proposed for the potent mutagenic potential of 4-MeQ.
Highly Chemoselective Deoxygenation of N-Heterocyclic N-Oxides Using Hantzsch Esters as Mild Reducing Agents
An, Ju Hyeon,Kim, Kyu Dong,Lee, Jun Hee
supporting information, p. 2876 - 2894 (2021/02/01)
Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount of a catalyst. This technology also allows for multigram-scale reactions even with an extremely low catalyst loading of 0.01 mol %. The scope of this scalable and operationally convenient protocol encompasses a wide range of functional groups, such as amides, carbamates, esters, ketones, nitrile groups, nitro groups, and halogens, which provide access to the corresponding deoxygenated N-heterocycles in good to excellent yields (an average of an 86.8% yield for a total of 45 examples).
Highly Ordered Mesoporous Cobalt Oxide as Heterogeneous Catalyst for Aerobic Oxidative Aromatization of N-Heterocycles
Cao, Yue,Wu, Yong,Zhang, Yuanteng,Zhou, Jing,Xiao, Wei,Gu, Dong
, p. 3679 - 3686 (2021/06/18)
N-heterocycles are key structures for many pharmaceutical intermediates. The synthesis of such units normally is conducted under homogeneous catalytic conditions. Among all methods, aerobic oxidative aromatization is one of the most effective. However, in homogeneous conditions, catalysts are difficult to be recycled. Herein, we report a heterogeneous catalytic strategy with a mesoporous cobalt oxide as catalyst. The developed protocol shows a broad applicability for the synthesis of N-heterocycles (32 examples, up to 99 % yield), and the catalyst presents high turnover numbers (7.41) in the absence of any additives. Such a heterogenous approach can be easily scaled up. Furthermore, the catalyst can be recycled by simply filtration and be reused for at least six times without obvious deactivation. Comparative studies reveal that the high surface area of mesoporous cobalt oxide plays an important role on the catalytic reactivity. The outstanding recycling capacity makes the catalyst industrially practical and sustainable for the synthesis of diverse N-heterocycles.