- The trifluoromethylating sandmeyer reaction: A method for transforming C-N into C-CF3
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A means to trifluoromethylate: The beneficial properties imparted by the trifluoromethylation of aromatic compounds continue to drive the discovery of novel reagents and reactions for the late-stage introduction of such moieties. Highlighted here is the recently discovered Sandmeyer trifluoromethylation approach, which now permits aromatic amines to be substrates in a direct trifluoromethylation strategy. Copyright
- Browne, Duncan L.
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- Simple preparation method of teriflunomide
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The invention provides a simple preparation method of teriflunomide, and belongs to the field of medicinal chemistry. The preparation method comprises the following steps of: (1) mixing 5-methylisoxazole-4-formic acid and a condensing agent in a solvent under an alkaline condition, and carrying out condensation reaction to obtain an active ester system; (2) mixing the active ester system and 4-trifluoromethylaniline in a solvent, and carrying out condensation reaction to obtain an intermediate leflunomide; and (3) carrying out alkali treatment and acid treatment on the obtained intermediate leflunomide to obtain teriflunomide. According to the method, the 5-methylisoxazole-4-formic acid reacts with the 4-trifluoromethylaniline in the form of active ester, so that the reaction activity of the 5-methylisoxazole-4-formic acid and the 4-trifluoromethylaniline is improved, the reaction condition is mild, the obtained intermediate leflunomide does not need to be purified, and the yield of teriflunomide is improved.
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Paragraph 0063-0068; 0072-0075; 0078-0081; 0084-0087; ...
(2021/07/08)
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- Preparation method of (by machine translation)
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The invention relates to a novel process for preparing flutamipide by using a pharmaceutical active pharmaceutical ingredient, wherein ethyl acetoacetate is taken as a raw material and mixed with hydroxylamine hydrochloride to obtain fluticide. The process not only can better control the content of 3 - methyl isomers and 4 - trifluoromethylaniline in the baflunomide product, and is higher in yield and more concise. The industrial wastewater generated by the process is less in waste gas, environmentally friendly, capable of effectively reducing production cost and corrosion to equipment. (by machine translation)
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- A catalytic fluoride-rebound mechanism for C(sp3)-CF3 bond formation
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The biological properties of trifluoromethyl compounds have led to their ubiquity in pharmaceuticals, yet their chemical properties have made their preparation a substantial challenge, necessitating innovative chemical solutions. We report the serendipitous discovery of a borane-catalyzed formal C(sp3)-CF3 reductive elimination from Au(III) that accesses these compounds by a distinct mechanism proceeding via fluoride abstraction, migratory insertion, and C-F reductive elimination to achieve a net C-C bond construction. The parent bis(trifluoromethyl)Au(III) complexes tolerate a surprising breadth of synthetic protocols, enabling the synthesis of complex organic derivatives without cleavage of the Au-C bond. This feature, combined with the fluoride-rebound mechanism, was translated into a protocol for the synthesis of 18F-radiolabeled aliphatic CF3-containing compounds, enabling the preparation of potential tracers for use in positron emission tomography.
- Levin, Mark D.,Chen, Tiffany Q.,Neubig, Megan E.,Hong, Cynthia M.,Theulier, Cyril A.,Kobylianskii, Ilia J.,Janabi, Mustafa,O'Neil, James P.,Toste, F. Dean
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p. 1272 - 1275
(2017/06/30)
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- Exploiting intramolecular hydrogen bonding for the highly (: Z)-selective & metal free synthesis of amide substituted β-aminoenones
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Herein, we report the metal free and intramolecular hydrogen bonding (IMHB) directed (Z)-selective synthesis of amide substituted β-aminoenones. Systematically, we confirm the role of dual IMHB (CO?H-N) on the Z-direction using single-crystal X-ray analysis and 1D and 2D NMR studies. High stereoselectivity, atom efficiency, excellent yields and high purity are achieved by mere filtration. We avoid column purification and the formed by-product in the process is environmentally friendly.
- Subramaniam, Palaniraja,Ramasubbu, Chandrasekaran,Athiramu, Selvaraj
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p. 2541 - 2545
(2017/07/17)
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- A NOVEL PROCESS FOR THE PREPARATION OF TERIFLUNOMIDE
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The present invention provides a process for the preparation of Teriflunomide (Formula-I). The present invention describes the synthesis of Teriflunomide without isolating the intermediate Leflunomide. Teriflunomide is prepared from 5-Methyl isoxazole-4-carboxylic acid by converting to its acid chloride and coupling with 4-trifluoromethyl aniline to obtain Leflunomide (which is not isolated) followed by ring opening reaction using aq. Sodium Hydroxide to form Teriflunomide. In other words, the process is telescoped from 5- methylisoxazole-4-carbonyl chloride.
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- Comprehensive Study of the Organic-Solvent-Free CDI-Mediated Acylation of Various Nucleophiles by Mechanochemistry
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Acylation reactions are ubiquitous in the synthesis of natural products and biologically active compounds. Unfortunately, these reactions often require the use of large quantities of volatile and/or toxic solvents, either for the reaction, purification or isolation of the products. Herein we describe and discuss the possibility of completely eliminating the use of organic solvents for the synthesis, purification and isolation of products resulting from the acylation of amines and other nucleophiles. Thus, utilisation of N,N′-carbonyldiimidazole (CDI) allows efficient coupling between carboxylic acids and various nucleophiles under solvent-free mechanical agitation, and water-assisted grinding enables both the purification and isolation of pure products. Critical parameters such as the physical state and water solubility of the products, milling material, type of agitation (vibratory or planetary) as well as contamination from wear are analysed and discussed. In addition, original organic-solvent-free conditions are proposed to overcome the limitations of this approach. The calculations of various green metrics are included, highlighting the particularly low environmental impact of this strategy.
- Mtro, Thomas-Xavier,Bonnamour, Julien,Reidon, Thomas,Duprez, Anthony,Sarpoulet, Jordi,Martinez, Jean,Lamaty, Frdric
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supporting information
p. 12787 - 12796
(2015/09/01)
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- CuCF3: A [18F]trifluoromethylating agent for arylboronic acids and aryl iodides
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Positron emission tomography has emerged as the leading method for medical imaging with fluorine-18 as the most widely used radioactive isotope. Here we report a semi-automated method for the preparation of valuable [ 18F]trifluoromethylcopper, as well as its use for the radiosynthesis of [18F]trifluoromethylarenes and heteroarenes. Mild conditions of [18F]trifluoromethylation make this method particularly useful for the radiosynthesis of pharmacologically relevant [18F] trifluoromethylarenes and heteroarenes. 18F Radiochemistry: A semi-automated method for the fast preparation of radiolabelled (trifluoromethyl)copper is reported (see scheme), thus making [ 18F]CuCF3 almost as accessible as [18F]fluoride itself for the preparation of radiolabelled trifluoromethylated probes. It can be used for the preparation of radiolabelled trifluoromethylarenes from arylboronic acids and aryliodides. This methodology is clean, efficient and consistent with the specific requirements of radiochemistry.
- Ivashkin, Pavel,Lemonnier, Gerald,Cousin, Jonathan,Gregoire, Vincent,Labar, Daniel,Jubault, Philippe,Pannecoucke, Xavier
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p. 9514 - 9518
(2014/08/18)
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- Copper-promoted sandmeyer trifluoromethylation reaction
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A copper-promoted trifluoromethylation reaction of aromatic amines is described. This transformation proceeds smoothly under mild conditions and exhibits good tolerance of many synthetically relevant functional groups. It provides an alternative approach for the synthesis of trifluoromethylated arenes and heteroarenes. It also constitutes a new example of the Sandmeyer reaction.
- Dai, Jian-Jun,Fang, Chi,Xiao, Bin,Yi, Jun,Xu, Jun,Liu, Zhao-Jing,Lu, Xi,Liu, Lei,Fu, Yao
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p. 8436 - 8439
(2013/07/19)
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- Mechanosynthesis of amides in the total absence of organic solvent from reaction to product recovery
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The synthesis of various amides has been realised avoiding the use of any organic solvent from activation of carboxylic acids with CDI to isolation of the amides. Mechanochemistry was the key point of the process allowing rapid formation of the amide bond and efficient water-based purification of the final products.
- Metro, Thomas-Xavier,Bonnamour, Julien,Reidon, Thomas,Sarpoulet, Jordi,Martinez, Jean,Lamaty, Frederic
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supporting information
p. 11781 - 11783
(2013/01/15)
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- AN IMPROVED PROCESS FOR PREPARATION OF LEFLUNOMIDE
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This invention describes a process for the preparation of N-(4-trifluoromethyl)-5-methylisoxazole-4-carboxamide commonly known as leflunomide comprising : (a) reacting ethylaceto acetate, triethylorthoformate, and acetic anhydride with simultaneous distillation to form ethyl ethoxymethyleneacetoacetic ester; (b) reacting the ethyl ethoxymethyleneacetoacetic ester with aqueous hydroxylamine without using any external base and without any distillation to form ethyl-5-methylisoxazole-4-carboxylate; (c) reacting the ethyl-5-methylisoxazole-4-carboxylate with strong acid to form -5-methylisoxazole-4-carboxylic acid; (d) 5-methylisoxazole-4-carboxylic acid is reacted with thionyl chloride in presence of N, N-Dimethylformamide and equimolar of 4-trifluoromethylaniline without any external base to obtain highly pure Leflunomide.
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Page/Page column 5-7
(2008/06/13)
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- Process for preparing 5-methylisoxazole-4-carboxylic- (4'-trifluoromethyl)-anilide
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A process for preparing 5-methylisoxazole-4-carboxylic-(4′-trifluoromethyl)-anilide comprising: (a) reacting ethylacetoacetate, triethylorthoformate, and acetic anhydride at a temperature of from about 75° C. to about 150° C., to form ethyl ethoxymethyleneacetoacetic ester; (b) combining the ethyl ethoxymethyleneacetoacetic ester with sodium acetate or a salt of trifluoroacetic acid in the presence of hydroxylamine sulfate at a temperature of from about ?20° C. to 10° C., to form ethyl-5-methylisoxazole-4-carboxylate; (c) reacting the ethyl-5-methylisoxazole-4-carboxylate with a strong acid to form 5-methylisoxazole-4-carboxylic acid; (d) reacting the crystallized 5-methylisoxazole-4-carboxylic acid with thionyl chloride to form 5-methylisoxazole-4-carbonyl chloride; and (e) reacting the 5-methylisoxazole-4-carbonyl chloride with trifluoromethyl aniline and an amine base at a temperature of from about 0° C. to about 50° C. to form 5-methylisoxazole-4-carboxylic-(4′-trifluoromethyl)-anilide. The process of the invention is especially advantageous for preparing 5-methylisoxazole-4-carboxylic-(4′-trifluoromethyl)-anilide, since the process: (1) eliminates or reduces the formation of the by-product 2-cyanoacetoacetic-1-(4′-trifluoromethyl)-anilide (CATA), generally as low as 0.0006%; (2) eliminates or reduces the formation of isomeric impurity ethyl-3-methyisoxazole-4-carboxylate and its corresponding acid as low as 0.1%, (3) produces a high quality of 5-methylisoxazole-4-carboxylic-(4′-trifluoromethyl)-anilide generally having 99.8-100% HPLC potency; and (4) does not require distillation of the isoxazole ester.
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- Method for systhesizing leflunomide
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A process for synthesizing leflunomide from 5-methylisoxazole-4-carboxylic acid and 4-trifluoromethylaniline is provided. Further provided is the leflunomide prepared by the inventive process, which is substantially free of difficult-to-separate impurities often found in leflunomide prepared by known methods, including N-(4-trifluoromethylphenyl)-2-cyano-3-hydroxycrotonamide, 5-methyl-N-(4-methylphenyl)-isoxazole-4-carboxamide and N-(4-trifluoromethylphenyl)-3-methyl-isoxazole-4-carboxamide. The invention further provides pharmaceutical compositions and dosage forms containing highly pure leflunomide and methods of treating disease using the leflunomide.
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- Process for crystallizing N-(4-trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide
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The invention relates to a process for obtaining N-(4-trifluoromethylphenyl)-5-methyl-isoxazole-4-carboxamide in crystalline form, which is essentially free of byproducts. For this purpose, N-(4-trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide is transferred into an organic solvent or into mixtures of organic solvents and water, the amount of byproduct in the solution is determined by quantitative analysis and an equimolar amount of a base is added. N-(4-Trifluoromethylphenyl)-5-methyl-isoxazole-4-carboxamide is isolated from the resulting solution by crystallization.
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- Use of leflunomide for inhibiting tumor necrosis factor alpha
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N-(4-Trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide is an effective compound for preventing and treating disorders in which tumor necrosis factor alpha is involved. It is used as a pharmaceutical.
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- Isoxazole-4-carboxamides and hydroxyalkylidenecyanoacetamides, pharmaceuticals containing these compounds and their use
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Isoxazole-4-carboxamide derivatives and hydroxyalkylidene-cyanoacetamide derivatives are suitable for the treatment of carcinoses. These compounds can be prepared by known processes. Some of the compounds are novel and are additionally suitable for the treatment of rheumatic disorders.
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- Pharmaceutical for the treatment of skin disorders
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Pharmaceutical for the treatment of skin disorders A compound of the formula I or II STR1 and physiologically tolerable salts of compound of the formula II are suitable for treatment of psoriasis.
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- Use of leflunomide for inhibiting interleukin 8
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The use of leflunomide for inhibiting interleukin 8 N-(4-Trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide is an effective compound for preventing and treating disorders in which interleukin 8 is involved. It is used as a pharmaceutical.
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- Method of treating hyperproliferative vascular disease
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A method of preventing or treating hyperproliferative vascular disease in a mammal consists of administering to a mammal an effective amount of carboxyamide compounds.
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- 5-Substituted 4-isoxazolecarboxamides with platelet antiaggregating and other activities
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The synthesis of a series of 5-substituted 4-isoxazolecarboxamides by reaction of eight 5-substituted 4-isoxazolecarbonyl chlorides with pyrrolidine, piperidine, morpholine and 4-trifluoromethylaniline is described. Some of these amides showed platelet antiaggregating activity in vitro slightly inferior to that of acetylsalicylic acid, as well weak antiinflammatory, analgesic and antipyretic activities in rats and mice.
- Fossa,Menozzi,Schenone,Filipelli,Russo,Lucarelli,Marmo
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p. 789 - 802
(2007/10/02)
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- 5-Methylisoxazole-4-carboxylic-(4-trifluoromethyl)-anilide
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5-Methylisoxazole-4-carboxylic acid-(4-trifluoromethyl)-anilide and a process for its preparation is described. The compound has an antirheumatic, antiphlogistic, antipyretic and analgesic action, and can be used for the treatment of multiple sclerosis.
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