- Quinoline- and 1,8-naphthyridine-3-carboxylic acids using a self-catalyzed Friedl?nder approach
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One-step syntheses of 2-alkyl- and 2,4-dialkyl-substituted quinoline-3-carboxylic acids and 1,8-naphthyridine-3-carboxylic acids are reported using a catalyst-free Friedl?nder reaction. The reaction is carried out in one step by simple heating of 2-aminobenzaldehyde, 2-amino-5-chlorobenzaldehyde, 2-aminonicotinaldehyde, or 2-aminoacetophenone with a β-ketoester in toluene or xylene for 24 h. Under these conditions, the carboxylic acid product is isolated directly from the reaction mixture without need for further purification. The observation that the reaction starts slowly and accelerates as it proceeds suggests that the transformation is self-catalyzed. This hypothesis is also supported by the finding that attempts to extend the current reaction to diketones, which cannot hydrolyze to an acid, were generally unsuccessful.
- Nammalwar, Baskar,Murie, Maeghan,Fortenberry, Chelsea,Bunce, Richard A.
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supporting information
p. 3181 - 3183
(2014/05/20)
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- Synthesis and antimicrobial activity of 1-alkyl and aryl-3-(2-methyl-l,8- naphthyridin-3 -yl)ureas
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1,8-naphthyridine derivatives have attracted considerable attention because they are the chief constituent of many compounds which have been isolated from natural sources, with various biological activities. Nalidixic acid, for example, possesses strong antibacterial activity and used mainly for the treatment of urinary tract infections with gram negative pathogens and Gemifloxacin has antimicrobial and antibacterial activities. It is known that (￡)- and (Z)-o-(diethylamino)ethyl oximes of 1,8-naphthyridine series have the potential for use as local anesthetics and l-(2-fluorobenzyl)-3-(2-tolyl)- l,8-naphthyridin-2(l//)-one is used for the treatment of memory disorders, in particular, Alzheimer's disease. In recent years, research on derivatives of 1,8-naphthyridine has been intensive because these compounds show a wide range of biological activities. 2-Methyl-l,8-naphthyridine-3-carbonylazide has been synthesized from ethyl-2-methyl-l,8-naphthyridine-3-carboxylate following two different procedures. The azide on heating with aliphatic and aromatic primaryamines in xylene underwent Curtius rearrangement to furnish the title compounds. They have been screened for their antimicrobial activity.
- Ramesh,Thirumala Chary,Laxminarayana,Sreenivasulud
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scheme or table
p. 1271 - 1273
(2010/12/20)
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- HERBICIDAL COUMPOUNDS
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The present invention relates to novel herbicidal [l,8]-naphthyridines of Formula (Ia) or (Ib), or an agronomically acceptable salt of said compound wherein R2, R3, R4, R5,R6,R7, R8, n, m, X and Q are as defined herein. The invention further relates to processes and intermediates for the preparation of the [l,8]-naphthyridines, to compositions which comprise the herbicidal compounds, and to their use for controlling weeds, in particular in crops of useful plants.
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Page/Page column 87
(2009/10/22)
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- Synthesis and biological activity of esters of 2-methyl-1,8-naphthyridine-3-carbamic acid
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2-Methyl-1,8-naphthyridine-3-carbazide 3 has been synthesized from ethyl 2-methyl-1,8-naphthyridine-3-carboxylate 1 following two different procedures. The azide 3 on heating with different alcohols including benzyl alcohols underwent Curtius rearrangement to furnish the title compounds 5. They have been screened for their antimicrobial activity.
- Ramesh,Sreenivasulu
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p. 897 - 900
(2007/10/03)
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