- Regioselective nucleophilic substitution of halogen derivatives of 1-substituted 4-oxo-1,4-dihydroquinoline-3-carboxylic acids
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The rate of the nucleophilic displacement of the fluoro atom of 7-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate could be enhanced either by the introduction of further fluoro atom(s) into position(s) 6 and/or 8, or by the formation of a boron chelate (e.g. 3). The regioselectivity of the nucleophilic substitution of the chloro atom in 1-substituted 6-fluoro-7-chloro-4-oxo-1,4dihydroquinoline-3-carboxylic acids could also be enhanced by the formation of a boron chelate (e.g. 7).
- Hermecz, Istvan,Vasvari-Debreczy, Lelle,Podanyi, Benjamin,Kereszturi, Geza,Balogh, Maria,Horvath, Agnes,Varkonyi, Peter
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p. 1111 - 1116
(2007/10/03)
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- Cycloaracylation of Enamines,II. - Synthesis of 1-Amino-4-quinolone-3-carboxylic Acids
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The 2-benzoyl-3-hydrazinoacrylic esters 3, 11, 17, and 23 are obtained by the reactions of 2-chloro-5-nitrobenzoyl chloride (1) with the enehydrazinocarboxylic esters 2 and 2-benzoyl-3-ethoxyacrylic esters 9 with hydrazine derivatives 10, 16, and 22.After cyclocondensation, the above esters afford 1-aminoquinolonecarboxylic esters 4, 12, 18, and 24, which are hydrolyzed to give the corresponding 1-aminoquinolonecarboxylic acids 5, 13, 19, and 26.The 1-amino-7-haloquinolonecarboxylic acids 13a-f, 19a-f, and 26b react with aliphatic amines to afford 1,7-diaminoquinolonecarboxylic acids 30c-m, which possess a high level of bactericidal activity.
- Grohe, Klaus,Heitzer, Helmut
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p. 871 - 880
(2007/10/02)
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- Novel amino-substituted 3-quinolinecarboxylic acid antibacterial agents: Synthesis and structure-activity relationships
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A series of novel 3-quinolinecarboxylic acid derivatives have been prepared and their antibacterial activity evaluated. These derivatives are characterized by fluorine attached to the 6-position and substituted amino groups appended to the 1- and 7-positions. Structure-activity relationship studies indicate that antibacterial potency is greatest when the 1-substituent is methylamino and the 7-substituent is either 4-methyl-1-piperazinyl, 16, or 1-piperazinyl, 21. Derivatives 16 and 21, the 1-methylamino analogues of pefloxacin and norfloxacin, respectively, show comparable in vitro and in vivo antibacterial potency to these two known agents. The activity (vs Escherichia coli Vogel) of 16 (amifloxacin) is the following: in vitro MIC (μg/mL) = 0.25; in vivo (mice) PD50 (mg/kg) = 1.0 (po), 0.6 (sc).
- Wentland,Bailey,Cornett,Dobson,Powles,Wagner
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p. 1103 - 1108
(2007/10/02)
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