- A 2,4-dichloro-5-fluoro-3-nitro benzoic acid preparation method
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The invention relates to a preparation method of 2, 4-dichloro-5-fluoro-3-nitrobenzoic acid and belongs to the technical field of chemical engineering, and particularly belongs to the field of chemical synthesis. The preparation method of 2, 4-dichloro-5-
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Paragraph 0026; 0027
(2017/03/08)
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- A novel approach to Finafloxacin hydrochloride (BAY35-3377)
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Finafloxacin hydrochloride, an important clinical compound was synthesized by a novel synthetic approach. An active intermediate ethyl 7-chloro-8-cyano-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate 19 was prepared by a new route. The chiral (S,S′)-N-Boc 10 was derived from protected pyrrolidine and the absolute stereochemistry was established by X-ray analysis.
- Hong, Jian,Zhang, Zonghua,Lei, Huoxing,Cheng, Haiying,Hu, Yufang,Yang, Wanliang,Liang, Yinglin,Das, Debasis,Chen, Shu-Hui,Li, Ge
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body text
p. 2525 - 2528
(2009/09/06)
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- Defluorinated sparfloxacin as a new photoproduct identified by liquid chromatography coupled with UV detection and tandem mass spectrometry
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Photodegradation of sparfloxacin was observed by means of high-pressure liquid chromatography with UV detection and liquid chromatography coupled with UV detection and tandem mass spectrometry (LC-MS/MS). Three products were detected. Comparison with an independently synthesized derivative of sparfloxacin revealed the structure of one product which is believed to be 8- desfluorosparfloxacin. The second product is likely to be formed by the splitting off of a fluorine and a cyclopropyl ring. Thus, photodefluorination of quinolone antibacterial agents is found and proved for the first time by LC-MS/MS.
- Engler, Michael,Rüsing, Guido,S?rgel, Fritz,Holzgrabe, Ulrike
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p. 1151 - 1159
(2007/10/03)
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- Process for the preparation of benzoic acid derivatives
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A process for the preparation of a compound of the formula STR1 in which X1 and X2 each independently is chlorine or fluorine, and Y is chlorine, bromine, fluorine or iodine, comprising subjecting a compound of the formula STR2 to a
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- 4-Hydroxy-quinoline-3-carboxylic
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A process for the preparation of a compound of the formula STR1 in which Y is a nitrile group, an ester group COOR1 or an acid amide CONR2 R3, R1, R2 and R3 each independently is hydrogen or C1 -C4 -alkyl, and R3 may also be phenyl, and X2, X3, X4 and X5 each independently is hydrogen, halogen, nitro, cyano, alkyl having 1-3 carbon atoms, alkoxy having 1-3 carbon atoms, alkylmercapto having 1-3 carbon atoms, alkylsulphonyl having 1-3 carbon atoms, or a phenylsulphonyl group which is optionally substituted in the aryl radical, comprising reacting an aminoacrylate of the formula in which X1 is halogen, a nitro group, an alkoxy, alkoxy, alkylmercapto or alkylsulphonyl group having 1-3 carbon atoms in each case, or an arylsulphonyl group, W is hydrogen or a --CH2 CH2 Z radical, Z is is a nitrile group, an ester group COOR4 or an acid amide group CONR5 R6, and R4, R5 and R6 each independently is hydrogen or C1 -C4 -alkyl, and R5 may also be phenyl, with an acid acceptor in an aprotic solvent. Some of the reactants are new, as are the products which are intermediates for antibacterially active 1-alkyl-4-quinolone-3-carboxylic acids.
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- 1,8-bridged 4-quinolone-3-carboxylic acid antibacterials
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Antibacterially active new 1,8-bridged 4-quinolone-3-carboxylic acid derivatives of the formula STR1 in which Y is carboxyl or a derivative thereof R1, R2, R3, R4, X1, X2 and X5
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- Synthesis of 4,12-Dihydro-4-oxoquinoquinoxaline-5-carboxylic Acid Derivatives
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The synthesis and antibacterial activity of 1-substituted amino-2-fluoro-4,12-dihydro-4-oxoquinoquinoxaline-5-carboxylic acid derivatives are described.The synthetic route includes a carbon homologation and two intramolecular nucleophilic disp
- Chu, Daniel T. W.,Maleczka, Robert E.,Nordeen, Carl W.
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p. 927 - 930
(2007/10/02)
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