- meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C?H Borylation
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Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C?H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as ?F, ?Cl, ?Br, ?CH3, ?Et, ?iPr ?OCH3, and ?OCF3. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.
- Li, Xuejing,Deng, Xingwang,Coyne, Anthony G.,Srinivasan, Rajavel
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supporting information
p. 8018 - 8023
(2019/05/29)
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- A coccidian preparation method
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The invention relates to a preparation method for diclazuril. A document reports that the synthesis of diclazuril is carried out in a such way that 2,6-dichloro-para-nitroaniline or 3,4,5-trichloronitrobenzene is used as an initial raw material and is subjected to diazotization reaction, substitution reaction, reduction reaction and the like to prepare a common intermediate 3. The existing process has many steps and is low in overall yield so that the costs of diclazuril raw materials and preparation stay at a high level. The invention provides a synthetic process of diclazuril. Particularly, the synthetic process comprises the steps that an intermediate 4 is prepared by performing reaction on the intermediate 3 and sodium nitrite by means of reduction and is subjected to cyclization and ring enlargement to obtain a product. In the route, a column chromatography means is not adopted; therefore, the process is short in the reaction steps and is suitable for industrial production.
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Paragraph 0020; 0023; 0045-0047
(2018/09/02)
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- Preparation method of anticoccidial drug Diclazuril
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The invention discloses a preparation method of an anticoccidial drug Diclazuril. The method takes 3,4,5-trichloronitrobenzene as a raw material and the 3,4,5-trichloronitrobenzene and 4-chlorobenzylcyanide are subjected to condensation reaction to generate 2,6-dichloro-alpha-(4-chlorobenzyl)-4-nitrophenylacetonitrile; enabling a condensate and hydrazine hydrate to be subjected to reduction to generate 2,6-dichloro-alpha-(4-chlorobenzyl)-4-aminophenylacetonitrile, enabling a reduzate and malonyl ethyl dicarbamate to be subjected to diazo, coupling, cyclization, hydrolysis and decarboxylationone-pot reaction to generate the Diclazuril. The method disclosed by the invention has a simple technology and is easy to operate; the environment protection problem caused by the fact that the odor of thioglycolic acid is great in a decarboxylation process of the Diclazuril is solved; meanwhile, the yield is improved and the total yield of the Diclazuril synthesized by taking 2,6-dichloro p-nitroaniline as the raw material is 43.8 percent, so that the preparation method is suitable for industrial production.
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Paragraph 0021; 0022; 0023
(2018/04/03)
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- Diclazuril and isotope internal standard D4-Diclazuril method for the preparation of
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The invention relates to a preparation method for diclazuril and isotope interior label D4-diclazuril. In the invention, 2, 6-dichloro-4-nitroaniline is adopted as a raw material, and the raw material is subjected to a sandmeyer reaction, affinity substitution, reduction, diazotization, diazonium reduction, a two-step condensation reaction, cyclization and refining, so that the diclazuril or the isotope interior label D4-diclazuril competitive product is obtained. According to the invention, during the process, the affinity substitution and the nitro-reduction can be continuously implemented without processing, and the diazotization, the diazonium reduction as well as the two-step condensation reaction can realize one-pot synthesis, the material prepared is high in purity and can reach 99.5%, the total yield is increased by about 10% as compared with that of the prior art, and the blank of the detection field of the medicine is filled up.
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Paragraph 0038; 0039; 0040; 0041
(2016/10/07)
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- Photochemistry and Photobiological Properties of Dicloran, a Postharvest Fungicide with Photosensitizing Side Effects
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Photochemical and laser flash photolysis studies on dicloran have shown that this fungicide undergoes photoreactions such as photoreduction of the nitro group and homolytic rupture of the C-NH2 bond. Dramatic changes in the dicloran photoreactivity by the influence of the solvents have been observed. More efficient photodegradation of this fungicide was observed in diethyl ether and chloroform than in methanol or acetonitrile. Photoreduction of the nitro group from the dicloran triplet state seems to be the most important photodegradation pathway in solvents of low polarity. Hydrogen abstraction by the triplet state or the intermediate radicals appears to be in the origin of linoleic acid peroxidations photosensitized by dicloran. The photohemolysis assay has been used, as an in vitro phototoxicity test, to demonstrate the involvement of radical-mediated cellular membrane damage in dicloran photosensitization.
- Bosca, Francisco,Miranda, Miguel A.,Serrano, Gabriel,Vargas, Franklin
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p. 532 - 537
(2007/10/03)
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- Ozone-mediated reaction of polychlorobenzenes and some related halogeno compounds with nitrogen dioxide: A novel non-acid methodology for the selective mononitration of moderately deactivated aromatic systems
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In the presence of ozone and preferably methanesulfonic acid as catalyst, polychlorobenzenes undergo selective mononitration with nitrogen dioxide at low temperatures, giving the corresponding polychloronitrobenzenes, in most cases in nearly quantitative yields.
- Suzuki,Mori,Maeda
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p. 841 - 845
(2007/10/02)
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- Substituted 2-phenyl-1,2,4-triazine-3,5(2H,4H)-diones, and coccidiostatic agents containing same
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Novel substituted 2-phenyl-1,2,4-triazine-3,5-(2H,4H)-diones are described as well as a process for their manufacture. The novel compounds may be used as chemotherapeutics, especially as coccidiostatic agents.
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- Anticoccidial derivatives of 6-azauracil. 3. Synthesis, high activity, and short plasma half-life of 1-phenyl-6-azauracils containing sulfonamide substituents
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A series of 1-phenyl-6-azauracils containing sulfonamide substituents was prepared. In contrast to previous 1-phenyl-6-azauracils, some of these sulfonamides combine high activity against Eimeria tenella infections in chickens with a very rapid rate of clearance from plasma. Most active was 1-[3'-chloro-5'-methyl-4'-(morpholinyl-sulfonyl)phenyl]-6-azauracil, with a minimum effective concentration in feed of about 10 ppm.
- Miller,Mylari,Howes Jr.,Figdor,Lynch,Lynch,Koch
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p. 1083 - 1087
(2007/10/02)
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