37928-17-9Relevant articles and documents
NHC-palladium-catalyzed ionic liquid-accelerated regioselective oxyarylation of alkynes with diaryl ethers?
Cen, Liying,He, Dan,Jiang, Huanfeng,Li, Jianxiao,Lin, Zidong,Wu, Wanqing
supporting information, p. 1983 - 1988 (2022/04/03)
The first NHC-palladium-catalyzed regioselective oxyarylation of oxime ether in a task-specific ionic liquid via C(sp3)-O and C(sp2)-O bond cleavage of two different types of ethers for the assembly of structurally diverse 4-arylisoxazoles is described. Both the basic ionic liquid [C3NH2mim]Br and NHC-Pd catalyst IPr-Pd-Im-Cl2 played an important role in this transformation. Notably, this new approach provides a practical and straightforward route to access a broad range of privileged 4-arylisoxazole structures with good yields and excellent regioselectivities. Significantly, this catalytic system can be recycled up to eight times without significant loss of catalytic activity.
Preparation method of parecoxib sodium intermediate 5-methyl-3,4-diphenyl isoxazole
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, (2018/07/06)
The invention relates to a preparation method of parecoxib sodium intermediate 5-methyl-3,4-diphenyl isoxazole. The preparation method comprises the following steps: step one, taking phenyl propinyl ketone as a starting material, firstly, carrying out condensation with methanol aminated hydrochloride to generate Z-type 1-phenyl-1-propinyl-3-methyl-oxime; step two, carrying out a cycloaddition reaction on the Z-type 1-phenyl-1-propinyl-3-methyl-oxime and iodine chloride to generate 3-phenyl-4-iodo-5-methyl isoxazole; and step three, carrying out a substitution reaction on the 3-phenyl-4-iodo-5-methyl isoxazole and phenylboronic acid to generate 5-methyl-3,4-diphenyl isoxazole.
Highly Site Selective Formal [5+2] and [4+2] Annulations of Isoxazoles with Heterosubstituted Alkynes by Platinum Catalysis: Rapid Access to Functionalized 1,3-Oxazepines and 2,5-Dihydropyridines
Shen, Wen-Bo,Xiao, Xin-Yu,Sun, Qing,Zhou, Bo,Zhu, Xin-Qi,Yan, Juan-Zhu,Lu, Xin,Ye, Long-Wu
supporting information, p. 605 - 609 (2017/01/07)
Platinum-catalyzed formal [5+2] and [4+2] annulations of isoxazoles with heterosubstituted alkynes enabled the atom-economical synthesis of valuable 1,3-oxazepines and 2,5-dihydropyridines, respectively. Importantly, this Pt catalysis not only led to unique reactivity dramatically divergent from that observed under Au catalysis, but also proceeded via unprecedented α-imino platinum carbene intermediates.
Method for preparing parecoxib sodium key intermediates
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, (2017/08/29)
The invention relates to a method for preparing parecoxib sodium key intermediates, and belongs to the field of medicine synthesis. The method for preparing the parecoxib sodium key intermediates includes steps of firstly, preparing 1-(1-methyl-2-styrene)-pyrrolidine (a compound I); secondly, preparing 5-methyl-3, 4-diphenyl-5-(pyrrolidine-1-base)-4, 5-dihydro-isoxazole (a compound II); thirdly, preparing a crude product of 5-methyl-3, 4-diphenyl isoxazole (a compound III); fourthly, refining a crude product of 5-methyl-3, 4-diphenyl-5-isoxazole (a compound III). The shortcomings of existing synthesis methods can be overcome by the aid of the method. The method for preparing the parecoxib sodium key intermediates has the advantages of mild reaction conditions, inexpensive and easily available raw materials, simplicity in after-treatment operation, short production cycle and high product purity and yield. Besides, the novel method is provided for preparing the parecoxib sodium key intermediates.
Preparation method of 5-methyl-3,4-diphenylisoxazole
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Paragraph 0027; 0028; 0029; 0030; 0031; 0032; 0033-0040, (2017/07/20)
The invention discloses a preparation method of 5-methyl-3,4-diphenylisoxazole, which includes a step of performing a dehydration reaction to a compound (2) in methanol and water in the presence of an inorganic alkali to prepare the 5-methyl-3,4-diphenylisoxazole.
Method for preparing parecoxib for treating postoperative pain
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Paragraph 0005; 0059; 0060; 0061, (2017/01/12)
The invention discloses a method for preparing parecoxib for treating postoperative pain. The method comprises the following steps: 1) conducting a contact reaction between 3,4-diphenyl-4-(1-pyrrolidyl)-3-butene-2-one and ammonium acetate in acetic acid; after the reaction, diluting dichloromethane; regulating the pH value to 6-7 with saturated sodium bicarbonate; concentrating the organic phase and washing; recrystallizing with ethanol; and drying to obtain 5-methyl-3,4-diphenyl isoxazole; 2) stirring the obtained 5-methyl-3,4-diphenyl isoxazole and chlorosulfonic acid for reacting; adding anion exchange resin, and dropwise adding saturated ammonium chloride and dichloromethane for extraction; washing and concentrating; and recrystallizing with ethanol to obtain valdecoxib; and 3) enabling the valdecoxib obtained in the step 2) to react with propionic anhydride in the presence of triethylamine to obtain parecoxib. The method for preparing parecoxib, disclosed by the invention, has the advantages of simple steps, mild conditions and high yield.
A process for the preparation of sodium compound handkerchief auspicious past cloth and wherein the intermediate impurity, preparation method and application
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Paragraph 0085; 0086, (2017/02/24)
The invention provides parecoxib sodium which is prepared by controlling an intermediate impurity and in particular provides a preparation method of a parecoxib sodium compound as well as the intermediate impurity and an application of the parecoxib sodium compound. According to the preparation method provided by the invention, 3-methyl-4,5-diphenyl-4,5-dihydro-isoxazole-5-alcohol is used as an isomer impurity for preparing 5-methyl-3,4-diphenyl-4,5-dihydro-isoxazole-5-alcohol as an intermediate of the parecoxib sodium, the quality of the 3-methyl-4,5-diphenyl-4,5-dihydro-isoxazole-5-alcohol is controlled in the preparation of the parecoxib sodium, specifically, the impurity content is required not to be higher than 0.5 percent, and an important significance is provided for the product quality of the parecoxib sodium; by obtaining the 3-methyl-4,5-diphenyl-4,5-dihydro-isoxazole-5-alcohol as an isomer impurity of the important 5-methyl-3,4-diphenyl-4,5-dihydro-isoxazole-5-alcohol and further studying 3-methyl-4,5-diphenyl-4,5-dihydro-isoxazole-5-alcohol in the aspects of preparation process, detection process and purification process, important quality monitoring significance is provided for the process with the 5-methyl-3,4-diphenyl-4,5-dihydro-isoxazole-5-alcohol as an industrial production raw material.
Method for preparing parecoxib intermediate
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Paragraph 0016; 0021; 0022; 0023; 0025; 0027; 0029-0041, (2018/02/03)
The invention discloses a method for preparing a parecoxib intermediate. The method includes subjecting 1, 2-diphenyl-2-acetyl ethyl ketone and ammonium acetate to contact reaction with the presence of iodobenzene diacetate and potassium iodide, performing organic-phase concentration and washing after reaction, performing ethyl alcohol recrystallization, and drying to obtain 5-methyl-3, 4-diphenyl isoxazole. The method for preparing the parecoxib intermediate has the advantages of simplicity in procedure and high yield.
A method of preparing intermediates handkerchief auspicious past cloth sodium
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Paragraph 0029; 0030; 0031, (2017/05/05)
The invention discloses a novel method for preparing a parecoxib sodium intermediate 5-methyl-3, 4-diphenyl isoxazole. The method comprises the following steps: performing rearrangement reaction on a compound in the formula I (referring to the Specification)under the action of a catalyst to prepare a compound in the formula II(referring to the Specification); and under the condition of a catalyst, reacting hydroxylammonium chloride with the compound in the formula II to prepare 5-methyl-3,4-diphenyl isoxazole. The method disclosed by the invention has the advantages of mild reaction condition, good simplicity and convenience for operation, low cost, environmental-friendliness and the like.
Preparation method of cyclooxygenase-2 inhibitor parecoxib
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Paragraph 0027; 0028; 0029, (2016/11/14)
The invention discloses a preparation method of a cyclooxygenase-2 inhibitor parecoxib. The method comprises the following steps that 1, benzaldoxime reacts with 1-phenylpropyne in the presence of tris(2-phenylpyridine)iridium (III), triethylamine and magnesium oxide under the illumination condition to obtain 5-methyl-3,4-diphenylisoxazole; 2, a stirring reaction is conducted on 5-methyl-3,4-diphenylisoxazole obtained in the first step and chlorosulfonic acid, dichloromethane extraction is conducted after the reaction is completed, a dichloromethane phase is directly added into ammonium hydroxide, an organic phase is separated, water washing, concentrating and ethanol recrystallization are conducted, and valdecoxib is obtained; 3, valdecoxib obtained in the second step reacts with propionic anhydride in the presence of triethylamine, and parecoxib is obtained. The preparation method of parecoxib is simple in step, high in yield and simple in posttreatment.
