- Synthesis method of quinocetone
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The invention discloses a new synthesis method of quinocetone. Quinocetone is synthesized from mequindox and benzaldehyde as raw materials by reaction in an amino acids-alkali composite catalytic system. The product yield is 90% or higher and purity can reach 99%. Besides, the catalytic system promotes rapid reaction of mequindox and benzaldehyde at a lower temperature in the water phase to prepare the high-quality product, reaction conditions are mild, yield is excellent, and the production process is simple and convenient, safe and reliable; after the product is removed, the catalytic systemcan be recycled 3 times without changing the catalytic effect, and accordingly, the production cost can be reduced.
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Paragraph 0031-0050
(2019/08/20)
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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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- Improved synthesis of quinocetone
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The invention discloses a preparation method of improved quinocetone and the preparation method can be used for solving the problems in the prior art that the reaction time is long, low in product yield, poor in product quality and the lime. The preparation method is characterized by comprising the following steps: dissolving benzaldehyde, a catalyst, a water adsorbent and mequindox in methanol; in a heating state, stirring to react for 1-6 hours; after reaction, cooling and separating out a product; and filtering, washing and drying to obtain the product which meets the quality standard of quinocetone related to Veterinary Drug National Standard (Volume One) of Department of Agriculture. The yield of quinocetone prepared by the method reaches over 93% which is far higher than that recorded in available literatures, and the purity reaches over 98.5% which is higher than the content requirement of Department of Agriculture. Moreover, the reaction time is short, and the labor efficiency and the utilization ratio of equipment are improved.
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Paragraph 0018; 0032-0041
(2017/11/27)
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- Quinocetone preparation method
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The present invention discloses an improved quinocetone preparation method comprising the following steps: in a reaction vessel equipped with a stirrer and a condenser tube, a solvent, mequindox, benzaldehyde, a water-absorbing agent and an ionic liquid catalyst are added successively, the temperature is raised from room temperature to 60-65 DEG C for reaction while stirring for 3.5 hours, and the mixture is cooled to 30 DEG C, filtered, washed and dried to obtain quinocetone with a purity of 98.5% or more and a yield of 94.5% or more, wherein the molar feeding ratio of mequindox to benzaldehyde to catalyst is 1.0: 1.11-1.21: 0.14. During the preparation of the quinocetone, a product does not need to be refined, and the pure product can be obtained by direct filtration, washing and drying. The improved quinocetone preparation method has the characteristics of easily obtained raw materials, short reaction time, simple operation, high product purity, high yield and low production cost.
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Paragraph 0016; 0017; 0018
(2016/11/28)
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- Preparation method of quinocetone
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The invention discloses a preparation method of quinocetone. The preparation method comprises that benzofurazan, acetylacetone and benzaldehyde as raw materials in the presence of magnetic magnesium-aluminum hydrotalcite solid alkali and alkaline quaternary ammonium salt as catalysts in anhydrous ethanol as a solvent undergo a reaction at a temperature of 10-100 DEG C for 1-10h, and then the reaction product liquid is treated to form quinocetone. Through use of the magnetic magnesium-aluminum hydrotalcite solid alkali catalyst, the preparation method has simple processes, can be operated easily, realizes easy product separation, has small environmental pollution, is suitable for industrial production with a certain scale and is a green and clean synthesis route.
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Paragraph 0028; 0029
(2016/12/01)
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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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- 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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