- The crystal structure of DL-lomenfloxacin hydrate
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The DL-lomenfloxacin hydrate is an innersalt, which crystallizes in space group C2/c with cell parameters a = 22.897(10), b = 8.682(1), c = 18.365(2) A, β = 93.6 33(9)°, V = 3,705(3) A3 and Z = 8. The piperazinyl ring adopts a chair conformation, and the quinolone ring is essentially planar. The plane defined by C atoms of the piperazinyl ring is not coplanar with the quinolone ring. The carboxylate group shows two disorder parts, and is not coplanar with the quinolone ring, the dihedral angle between them is 113.8°. The disorder carboxylate group is split into two parts, the planes of which are skewed at the dihedral angles of 24.5 and 21.6° with the plane of the quinolone ring, respectively. The IR of the title compound is measured and studied. Springer Science+Business Media, LLC 2008.
- Shu, Zhan,Li, Hai Yan,Ma, Lin Lin,Chen, Wei Liang,Jin, Zhi Min
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- Preparation method of lomefloxacin hydrochloride
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The invention discloses a preparation method of lomefloxacin hydrochloride. The preparation method comprises the steps: with a lomefloxacin hydrochloride cyclization material as a starting raw material, the lomefloxacin hydrochloride finished product is obtained through ethylation reaction, hydrolysis reaction, condensation reaction with 2-methylpiperazine and salt formation; an ethylation reagentused in the ethylation reaction is bromoethane, and bromoethane is directly added; the ethylation reaction temperature is further divided into two sections, firstly, reaction is carried out for 2 h at the temperature of 80-90 DEG C, and then reaction is carried out for 2 h at the temperature of 100-105 DEG C; the hydrolysis reaction is carried out in the presence of glacial acetic acid and purified water. In the ethylation, the reaction yield can be greatly improved by adjusting the reaction temperature; the hydrolysis reaction adopts a part of purified water instead of glacial acetic acid, the yield not only can be guaranteed, but also the production cost is greatly reduced and the discharge of three wastes is reduced.
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Paragraph 0025-0029
(2019/12/25)
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- NOVEL METHOD OF SYNTHESIS OF FLUOROQUINOLONES
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The invention relates to a method of preparation of fluoroquinolones of formula (I) from compounds of formula (II): in which R1, R2, R3, R4, R5, R6, R7, and X are as defined in Claim 1.
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Page/Page column 6
(2009/04/24)
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- 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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- Synthesis and biological activity of 5-amino- and 5-hydroxyquinolones, and the overwhelming influence of the remote N1-substituent in determining the structure-activity relationship
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A series of 5-amino- and 5-hydroxyquinolone antibacterials substituted at C7 with a select group of common piperazinyl and 3-aminopyrrolidinyl side chains was prepared. These 5-substituted derivatives were compared to the analogous 5-hydrogen compounds for antiinfective activity by using DNA gyrase inhibition, minimum inhibitory concentrations against a variety of bacteria, and in vivo efficacy in the mouse infection model. The influence on the structure-activity relationships of varied substituents at C8 (H, F, Cl) and N1 (ethyl, cyclopropyl, difluorophenyl) was also studied. The results showed that several of the structure-activity conclusions regarding side-chain bulk at C7, the effect of halogen at C8, and the effect of the C5-amino group were greatly influenced by the choice of the N1-substituent. Several outstanding broad spectrum quinolones were identified in this work. In particular, the spectrum and potency of the 7-piperazinyl quinolones could be greatly enhanced by the judicious choice of C5-, C8-, and N1-substitutents.
- Domagala,Bridges,Culbertson,Gambino,Hagen,Karrick,Porter,Sanchez,Sesnie,Spense,Szotek,Wemple
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p. 1142 - 1154
(2007/10/02)
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- 6-Fluoro-1, 4-dihydro-4-oxo-7-substituted piperazinylquinoline-3-carboxylic acids and the method for preparing the same
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The invention is concerned with the novel piperazinylquinoline-3-carboxylic acids represented by formula (I) STR1 or a pharmacologically-acceptable salt thereof, a process for the preparation of them, and a pharmaceutical composition which contains these new compounds as active ingredient and can be used as the therapeutic agent against bacteria.
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