- Effective promotion of beirut reaction by-cyclodextrin in water
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A mild and highly efficient, environmentally friendly procedure has been developed for the conversion from benzofurazan-N-oxides to quinoxaline di-N-oxides in the presence of-cyclodextrin in water at room temperature with excellent yields. The application of cyclodextrin precludes the use of organic solvent, and the catalyst can be recovered and reused in subsequent reactions with the same catalytic activity. Herein, the Beirut reaction is carried out in the medium of water for the first time. The reaction mechanism was proposed based on the inclusion complexation of-cyclodextrin with benzofurazan-N-oxides which was confirmed by 1H NMR, ultraviolet/visible spectrum, and infrared spectroscopy. Copyright
- Sun, Tao,Zhao, Wen-Jing,Hao, Ai-You,Sun, Li-Zhen
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- Thermochemical and Theoretical Study of Some Quinoxaline 1,4-Dioxides and of Pyrazine 1,4-Dioxide
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The following standard molar enthalpies of formation in the gaseous state at 298.15 K were determined from the enthalpies of combustion of the crystalline solids, and their enthalpies of sublimation and the mean (N-O) bond dissociation enthalpies were derived. ΔfHm0(g); 〈D(N-O)〉 (kJ mol-1): quinoxaline 1,4-dioxide, 227.1 ± 2.4; 255.8 ± 2.0; 2-methylquinoxaline 1,4-dioxide, 169.9 ± 7.2; 268.3 ± 4.9; 2-methyl-3-acetylquinoxaline 1,4-dioxide, 33.1 ± 5.0; 251.6 ± 4.2; 2-phenyl-3-benzoylquinoxaline 1,4-dioxide, 355.2 ± 7.1; 227.3 ± 5.4; 2-methyl-3-carbomethoxyquinoxaline 1,4-dioxide, -148.7 ± 3.2; 242.3 ± 3.9; pyrazine 1,4-dioxide, 186.5 ± 1.9; 254.0 ± 2.3; 2-methyl-5-pyrazinecarboxylic acid, -213.6 ± 1.7. Unconstrained geometry optimizations by ab initio calculations showed the effect of steric hindrance on changes in extended delocalizations and were in accord with the trends in the mean bond dissociation enthalpies.
- Acree Jr.,Powell, Joyce R.,Tucker, Sheryl A.,Ribeiro da Silva, Maria D.M.C.,Matos, M. Agostinha R.,Goncalves,Santos,Morais,Pilcher
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- Synthesis, 3D-QSAR analysis and biological evaluation of quinoxaline 1,4-di-N-oxide derivatives as antituberculosis agents
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A series of quinoxaline 1,4-di-N-oxide derivatives variously substituted at C-2 position were synthesized and evaluated for in vitro antimycobacterial activity. Seventeen compounds exhibited potential activity (MIC ?6.25?μg/mL) against Mycobacterium tuber
- Pan, Yuanhu,Li, Panpan,Xie, Shuyu,Tao, Yanfei,Chen, Dongmei,Dai, Menghong,Hao, Haihong,Huang, Lingli,Wang, Yulian,Wang, Liye,Liu, Zhenli,Yuan, Zonghui
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- Preparation method of mequindox
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The invention provides a preparation method of mequindox. The preparation method comprises the step of performing reaction by taking ortho-nitroaniline, sodium hypochlorite and acetylacetone as raw materials, taking an NaOH/attapulgite compound as a catalyst and taking sodium carboxymethyl cellulose as a solubilizing agent and a homogenizing agent so as to obtain the mequindox. The preparation method of the mequindox, provided by the invention, realizes the purpose of one-step preparation of the mequindox, omits the intermediate treatment step of benzofurazan, and is simple in technology and high in production efficiency. The purity of the prepared mequindox product can reach 99% or more, and the total yield of the prepared mequindox product can reach 84.5% or more, which is equivalent tosingle-step yield of 90% or more, so that the prepared mequindox product has broad application prospects.
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Paragraph 0046-0063
(2019/02/08)
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- Improved synthesis of quinocetone and its two deoxy metabolites
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Oxidation of o-nitroaniline with sodium hypochlorite afforded benzofurazan oxide in 96 % yield, and treatment of benzofurazan oxide with acetylacetone in the presence of triethylamine gave 2-acetyl-3-methyl-quinoxaline--1,4-dioxide in 94 % yield. Finally, condensation of 2-acetyl-3-methyl-quinox-aline-1,4-dioxide with benzaldehyde using 4-(dimethylamino)pyridinium acetate as a catalyst led to quinocetone in 95 % yield. Subsequently, reduction of the synthesized quinocetone with sodium dithionite resulted in two deoxy derivatives, 1-(3-methyl-4-oxido-2-quinoxalinyl)-3-phenyl-2-propen-1-one and 1-(3-methyl-2-quinoxalinyl)-3-phenyl-2-propen-1-one in 88.5 and 92 % yield, respectively. Furthermore, the synthesized quinocetone, and its deoxy derivatives were characterized by1H-NMR,13C-NMR and elemental analysis.
- Li, Yuwen,Qiu, Mei,Bai, Yubin,Qu, Shaoqi,Hao, Zhihui
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p. 265 - 270
(2018/04/12)
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- Preparation method of quinohydroxylone
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The invention relates to a preparation method of quinohydroxylone, comprising the following steps: 1), mixing benzofuroxan and acetylacetone, adding triethylamine as a catalyst into a mixture, reacting at 40-60 DEG C, standing after reacting, filtering un
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Paragraph 0021; 0045
(2016/10/10)
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- Mequindox of tritium or deuterium-labeled preparation method
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The invention belongs to the technical field of veterinary drug preparation, and particularly relates to a preparation method for a tritium and deuterium labeled veterinary drug mequindox. The method comprises the following steps: adopting a trace synthesis method to allow tritium gas or deuterium gas and 4-bromine-2-nitroaniline or 4-iodine-2-nitroaniline to be subjected to dehalogenation reaction under the action of a catalyst and an acid acceptor, and meanwhile, introducing tritium gas or deuterium gas alternatively to generate 4-3H-2-nitroaniline or 4-2H-2-nitroaniline; performing the oxidation reaction and the Beirut reaction to prepare the C-6 tritium labeled or deuterium labeled mequindox, wherein the obtained product is clear in labeling point, high in specific activity (12.63 Ci/mmol), high in radiochemical purity (more than 98 percent) and high in chemical purity (more than 99.5 percent). The prepared tritium labeled mequindox provides a material foundation for the research of absorption, distribution, metabolism and residue elimination rules of the mequindox in an animal body; the prepared deuterium labeled mequindox can serve as an internal standard substance for the quantitative analysis of a mequindox trace amount.
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Paragraph 0052; 0055
(2017/02/09)
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- Synthesis, biological evaluation and structure-activity relationships of new quinoxaline derivatives as anti-Plasmodium falciparum agents
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We report the synthesis and antimalarial activities of eighteen quinoxaline and quinoxaline 1,4-di-N-oxide derivatives, eight of which are completely novel. Compounds 1a and 2a were the most active against Plasmodium falciparum strains. Structure-activity
- Gil, Ana,Pabon, Adriana,Galiano, Silvia,Burguete, Asuncion,Perez-Silanes, Silvia,Deharo, Eric,Monge, Antonio,Aldana, Ignacio
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p. 2166 - 2180
(2014/03/21)
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- Synthesis and Biological Evaluation of New Quinoxaline Derivatives as Antioxidant and Anti-Inflammatory Agents
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We report the synthesis, anti-inflammatory, and antioxidant activities of novel quinoxaline and quinoxaline 1,4-di-N-oxide derivatives. Microwave-assisted methods have been used to optimize reaction times and to improve yields. The tested compounds presented important scavenging activities and promising in vitro inhibition of soybean lipoxygenase (LOX). Two of the best LOX inhibitors (compounds 7b and 8f) were evaluated as invivo anti-inflammatory agents using the carrageenin-induced edema model. One of them (compound 7b) showed important in vivo anti-inflammatory effect (41%) similar to that of indomethacin (47%) used as the reference drug. Synthesis and Biological Evaluation of New Quinoxaline Derivatives as Antioxidant and Anti-Inflammatory Agents Asuncion Burguete, Eleni Pontiki, Dimitra Hadjipavlou-Litina*, Saioa Ancizu, Raquel Villar, Beatriz Solano, Elsa Moreno, Enrique Torres, Silvia Perez, Ignacio Aldana and Antonio Monge The synthesis, anti-inflammatory and antioxidant activities of new quinoxaline derivatives are reported. The new compounds exhibit important scavenging activities and promising values of in vitro inhibition of soybean LOX, One of them shows strong in vivo anti-inflammatory effect similar to that of indomethacin used as the reference drug.
- Burguete, Asuncion,Pontiki, Eleni,Hadjipavlou-Litina, Dimitra,Ancizu, Saioa,Villar, Raquel,Solano, Beatriz,Moreno, Elsa,Torres, Enrique,Perez, Silvia,Aldana, Ignacio,Monge, Antonio
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scheme or table
p. 255 - 267
(2012/01/13)
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- E-2-[3-(3,4-Dichlorophenyl)-1-oxo-2-propenyl]-3-methylquinoxaline-1, 4-dioxide: A lead antitubercular agent which alters mitochondrial respiration in rat liver
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A series of 2-(3-aryl-1-oxo-2-propenyl)-3-methylquinoxaline-1,4-dioxides 1a-l and 2-acetyl-3-methylquinoxaline-1,4-dioxide 2 were evaluated against Mycobacterium tuberculosis H37Rv. With the exception of the 4-nitro analog 1k, significant antitubercular potencies were observed in series 1 and 2 which have IC50 values in the range of 1-23 μM. Negative correlations were noted between the IC50 values of 1a-j, l towards M. tuberculosis and both the σ and π constants of the substituents in the benzylidene aryl ring. In particular, 1h emerged as a lead compound having IC50 and IC90 figures of 1.03 μM and 1.53 μM, respectively. This molecule affected respiration in rat liver mitochondria which is likely one way that 1h and the bioactive analogs exert their antitubercular properties. The quinoxaline 2, which lacks an α,β-unsaturated group, has no effect on mitochondrial respiration using concentrations which inhibit the growth of M. tuberculosis.
- Das, Umashankar,Das, Swagatika,Bandy, Brian,Gorecki, Dennis K.J.,Dimmock, Jonathan R.
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body text
p. 4682 - 4686
(2010/10/19)
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- Silica gel catalyzed synthesis of quinoxialine 1,4-dioxides under solvent-free conditions using microwave irradiation
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We report on the simple and quick synthesis of quinoxaline 1,4-dioxides in solvent-free conditions under microwave irradiation. Heating of various benzofuroxans and β-ketoesters or 1,3-diketones adsorbed on silica gel in a microwave oven for two minutes affords diverse biologically attractive quinoxaline 1,4-dioxides in high to excellent yields. Silica gel functions not only as support using microwave but also as catalyst and dehydration reagent.
- Sumiyoshi, Yusuke,Saito, Hiroaki,Miyairi, Shinichi,Takabatake, Tohru
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scheme or table
p. 905 - 909
(2009/09/29)
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- 2-(3-Aryl-2-propenoyl)-3-methylquinoxaline-1,4-dioxides: A novel cluster of tumor-specific cytotoxins which reverse multidrug resistance
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A series of 2-(3-aryl-2-propenoyl)-3-methylquinoxaline-1,4-dioxides 3a-l were prepared by condensation of various aryl aldehydes with 2-acetyl-3-methylquinoxaline-1,4-dioxide 2. These compounds inhibit the growth of human Molt 4/C8 and CEM T-lymphocytes a
- Das, Umashankar,Pati, Hari N.,Panda, Atulya K.,Clercq, Erik De,Balzarini, Jan,Molnar, Joseph,Barath, Zoltan,Ocsovszki, Imre,Kawase, Masami,Zhou, Li,Sakagami, Hiroshi,Dimmock, Jonathan R.
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experimental part
p. 3909 - 3915
(2009/10/02)
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- Synthesis of new 2-acetyl and 2-benzoyl quinoxaline 1,4-di-N-oxide derivatives as anti-Mycobacterium tuberculosis agents
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A series of 2-acetyl and 2-benzoyl-6(7)-substituted quinoxaline 1,4-di-N-oxide derivatives were synthesized and evaluated for in vitro antituberculosis activity. The results show that 2-acetyl-3-methylquinoxaline 1,4-di-N-oxide derivatives with chlorine,
- Jaso, Andres,Zarranz, Belen,Aldana, Ignacio,Monge, Antonio
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p. 791 - 800
(2007/10/03)
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- A new Route for the Synthesis of Phenazine Di-N-Oxides
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Several phenazine 5,10-dioxides (7a-d) were prepared by the reaction of 2-methyl-3-acetylquinoxaline 1,4-dioxide (2) with different aromatic aldehydes or by direct cyclization of the quinoxaline cinnamoyl derivatives 3 in basic medium.In addition, the phe
- El-Halim, M. S. Abd,El-Ahl, A. S.,Etman, H. A.,Ali, M. M.,Fouda, A.,Fadda, A. A.
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p. 1217 - 1224
(2007/10/03)
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- The reactions of benzofuroxan with carbonyl compounds on the surface of solid catalysts
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The cyclocondensations of benzofuroxan 1a with carbonyl compounds were smoothly and efficiently carried out by the adsorption of the components on the surface of silica gel or a molecular sieve to form a 2,3-disubstituted quinoxaline 1,4-dioxide. When the
- Takabatake,Hasegawa,Hasegawa
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p. 1477 - 1480
(2007/10/02)
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- REACTIONS OF 2-ACETYL-3-METHYLQUINOXALINE 1,4-DIOXIDE AND ITS DERIVATIVES
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2-Cinnamoyl-3-methylquinoxaline 1,4-dioxide (2) was inert to hydrochloric acid in refluxing ethanol.When a xylene solution of 2-acetyl-3-methylquinoxaline 1,4-dioxide (1-dioxide) was refluxed overnight, the dioxide was reduced mainly to 1,4-oxide and the oxidative products from xylene were also obtained. 2-Cinnamoyl-3-methylquinoxaline 4-oxide (4a) and 3-methyl-4-oxido-2-quinoxalyl 4-phenyl-1,3-butadienyl ketone (4b) were quantitatively cyclized into 4-methyl-3-oxo-1-phenyl- and 4-methyl-3-oxo-1-styryl-3H-pyrroloquinoxalin-10-ium chloride (6a and 6 b), respectively , when the ethanolic solution were refluxed in the presence of hydrochloric acid.
- Matoba, Katsuhide,Terada, Takashi,Sugiura, Masaru
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- Reactions of Benzofuroxan with 1,3-Diketones or β-Ketoesters on Silica Gel or Alumina
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The cyclocondensation of benzofuroxan with 1,3-diketones, 3-oxoalkanoic esters, butanedioic esters, or 3-oxoalkanamides in the presence of silica gel (adsorption of the components on silica gel) represents a convenient method for the synthesis of 2,3-disu
- Hasegawa, Minoru,Takabatake, Tohru
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- Quinoxaline derivatives
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The synthesis of quinoxaline and benzimidazole-N-oxides and of ester and amide derivatives of 3-hydroxy-2-quinoxalinecarboxylic acid by a novel process consisting of the reaction between a benzofuroxan and an activated methylene-containing compound under basic conditions.
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- Cosmetic composition for imparting to human skin a coloration resembling a natural tan
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A cosmetic composition for imparting to human skin after exposure to sunlight a coloration resembling a natural tan comprises a cosmetic vehicle suitable for topical application to the skin and an effective amount of at least one compound of the formula STR1 wherein R1 and R2 each independently represent hydrogen, an aliphatic radical having 1-18 carbon atoms, carbalkoxy having 2-5 carbon atoms, acyl having 2-5 carbon atoms, aryl, aryl substituted by alkyl having 1-4 carbon atoms or hydroxy, a heterocycle containing 4-6 members, substituted or not by alkyl having 1-4 carbon atoms, halogen or hydroxy, or R1 and R2 together form a saturated ring containing 4-12 chains, optionally substituted by alkyl having 1-4 carbon atoms, halogen or hydroxy, or bridged and containing a heteroatom selected from N, O or S; and R3 represents hydrogen, a lower aliphatic group containing 1-6 carbon atoms, lower alkoxy containing 1-4 carbon atoms or halogen, with the proviso that R1, R2 and R3 are not hydrogen simultaneously; and an acid addition salt thereof.
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