- Synthesis method of parecoxib sodium isomeric impurities
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The invention provides a synthesis method of parecoxib sodium isomeric impurities. Structures of the parecoxib sodium isomeric impurities are shown in formulae I and II in the description. The synthesis method comprises the following steps: the compound as shown in the formula I is subjected to reaction with the compound as shown in formula II or the compound as shown in formula III under the action of alkali, and a compound as shown in formula IV is generated; the corresponding parecoxib sodium isomeric impurities are generated by reduction reaction, diazotization, sulfonylation, amino substitution reaction and acylation reaction; the total reaction yield is higher than 22%, and purity of a target product is higher than 99%.
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- A handkerchief auspicious past cloth sodium impurities and its preparation method
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The invention discloses a handkerchief auspicious past cloth sodium impurities N - [[3 - (5 - methyl - 4 - phenyl - 3 - isoxazolyl) phenyl] sulfonyl] propionamide and its preparation method, the method is characterized in that the 1 - phenyl - 1, 2 - c diketone as raw materials, after cyclization, sulfonated, aminolysis, bromo, coupling, acylation to obtain handkerchief auspicious past cloth sodium impurities, the invention compounds obtained by 1 H - NMR, 1 H - NMR + D2O, 13 C - NMR spectrum confirmed the structure, preparation method is novel, the obtained compound by HPLC detection, the related substance purity ≥ 98%.
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- Preparation method of parecoxib sodium impurity
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The invention discloses a preparation method of parecoxib sodium impurity 3-[(4- phenyl)-5-methyl-3-isoxazole] benzene sulfonamide. The parecoxib sodium impurity is formed by performing cyclizing, sulfonation, ammonolysis, bromination and coupling on 1-phenyl-1, 2-propanedione serving as a raw material. 1H-NMR, 13C-NMR, DEPT, gCOSY, HMQC and HMBC maps confirm that the structure of the parecoxib sodium impurity, the preparation method is novel, the parecoxib sodium impurity is detected, and the purity of related substance is greater than or equal to 98 percent.
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- Directional preparation method and application of diaryl substituted isoxazole compound
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The present invention discloses a parecoxib sodium impurity S, namely, N-{3-[(5-methyl-4-phenylisoxazol-3-yl)phenyl]sulfonyl}propionamide, and an preparation method thereof, and belongs to the technical field of chemical pharmacy. The method comprises the following steps: 5-methyl-3,4-diphenylisoxazole is used as a starting raw material, and the reaction conditions and an auxiliary reagent are controlled to increase the ratio of a sulfonyl chloride group connected to the meta-position of a phenyl ring at a 3-position of an isoxazole ring; and an amination reaction is performed, a crystallization mother liquid is concentrated to dryness, the obtained product is subjected to propionylation, and finally through preparative liquid chromatography separation, the parecoxib sodium impurity S is obtained. The high-purity parecoxib sodium impurity S provided by the present invention can be used as an impurity standard product in the detection and analysis of a finished product of parecoxib sodium, so that the accurate positioning and chemical composition determination of impurities in the detection and analysis of the finished product of the parecoxib sodium are promoted, reinforcement of control of the impurities is facilitated, and the quality of the finished product of the parecoxib sodium is further improved. The method provided by the invention has the advantages of cheap and easyraw materials, simple operation, good reproducibility, and an HPLC purity of 99.5% or more.
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Paragraph 0026; 0029
(2018/06/28)
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- Application of [3+2]-cycloaddition in the synthesis of valdecoxib
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A large scale synthesis of valdecoxib 1 is described. Our work features potential application of [3+2]-dipolar cycloaddition involving enamine and in situ-generated nitrile oxide derivatives. Dr. Reddy's Laboratories Ltd.
- Reddy, Anumula Raghupathi,Goverdhan, Gilla,Sampath, Aalla,Mukkanti, Khagga,Reddy, Padi Pratap,Bandichhor, Rakeshwar
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p. 639 - 649
(2012/01/13)
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