158591-48-1Relevant academic research and scientific papers
Dichloro-4-quinolinol-3-carboxylic acid: Synthesis and antioxidant abilities to scavenge radicals and to protect methyl linoleate and DNA
Li, Guo-Xiang,Liu, Zai-Qun,Luo, Xu-Yang
, p. 1821 - 1827 (2010)
5,7-, 5,8-, 6,8-, 7,8-Dichloro-4-quinolinol-3-carboxylic acid (5,7-, 5,8-, 6,8-, 7,8-DCQA) together with 7-chloro-4-quinolinol-3-carboxylic acid (7-CQA) and 4-quinolinol-3-carboxylic acid (QA) were synthesized to investigate the antioxidant properties. 5,7-DCQA exhibited the highest ability to scavenge 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+.), 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and galvinoxyl radicals. 6,8-DCQA possessed the highest efficacy to protect methyl linoleate against 2,2′-azobis(2-amidinopropane)dihydrochloride (AAPH)-induced oxidation. 5,7-, 5,8-DCQA and QA were able to retard the β-carotene-bleaching in β-carotene-linoleic acid emulsion. In addition, 5,8- and 6,8-DCQA efficiently protected DNA against hydroxyl radical (.OH)-mediated oxidation, and 5,8-DCQA and 7-CQA were active to protect DNA against AAPH-induced oxidation. Furthermore, only 7-CQA can protect DNA against Cu2+/glutathione (GSH)-mediated oxidation. Dichloro-4-quinolinol-3-carboxylic acids were potent to be antiradical drugs, and were worthy to be researched pharmacologically.
Method for preparing 4-hydroquinolines and/or tautomeric compounds
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Page column 8, (2008/06/13)
The invention concerns a method for preparing 4-hydroquinolines and/or tautomeric compounds. More particularly, the invention concerns 5,7-dichloro-4-quinolines and/or its tautomeric compounds. The method is characterized in that it consists in heating a 4-hydroquinolinecarboxylic acid, its derivatives or precursors, at a temperature not more than 200° C. in the presence of a base.
Intermediates for producing 5,7-dichloro-4-hydroxyquinoline
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, (2008/06/13)
An industrially advantageous process for producing 5,7-dichloro-4-hydroxyquinoline (DCHQ) useful as an intermediate for agrohorticultural bactericides. The process comprises (i) hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline into 5,7-dichloro-3-carboxy-4-hydroxyquinoline (DCQA) in the presence of hydrochloric, sulfuric or phosphoric acid and (ii) decarboxylating the formed DCQA into DCHQ in the presence of sulfuric or phosphoric acid. In particular, this process comprises continuously conducting the hydrolysis of 5,7-dichloro-3-ethoxycarbonyl-4-hydroxyquinoline and the decarboxylation of the hydrolyzate in the presence of sulfuric acid having a specified concentration. The invention also relates to a process for producing DCQA by hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline in the presence of hydrochloric, sulfuric or phosphoric acid and a process for producing DCHQ by decarboxylating DCQA in the presence of sulfuric or phosphoric acid.
