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ChemicalBook CAS DataBase List Parecoxib
198470-84-7

Parecoxib synthesis

9synthesis methods
Propionic anhydride

123-62-6

Valdecoxib

181695-72-7

Parecoxib

198470-84-7

General procedure for the synthesis of N-((4-(5-methyl-3-phenylisoxazol-4-yl)phenyl)sulfonyl)propionamide from propionic anhydride and 4-(5-methyl-3-phenyl-1,2-oxazol-4-yl)benzenesulfonamide: 3.1 grams (10 mmol) of 4-(5-methyl-3-phenyl-1,2-oxazol-4-yl)benzenesulfonamide was mixed with 3.5 grams (35 mmol) of triethylamine and 2.6 g (20 mmol) propionic anhydride in 20 mL of chloromethane. After completion of the reaction, the reaction mixture was poured into water and extracted with dichloromethane. The extract was concentrated, dissolved in ethanol, crystallized 5 to 10 times, filtered and dried to give 3.4 g of N-((4-(5-methyl-3-phenylisoxazol-4-yl)phenyl)sulfonyl)propionamide in 92.5% yield and 99.77% purity.

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Yield:198470-84-7 97.7%

Reaction Conditions:

with benzenesulfonic acid at 50; for 2 h;Reagent/catalyst;Temperature;

Steps:

1.3; 2.3; 3.3; 4.3; 5.3 3. Preparation of parecoxib (formula 4 compound)
Weighed 15g (47.7mmol, 1e.q) of valdecoxib (compound of formula 3),Add to 22.5ml of propionic anhydride (238.5mmol, 5e.q), stir and heat to raise the temperature to 50 ° C,Add 0.076 g (4.8 mmol, 0.1 e.q) benzenesulfonic acid, react for 120 minutes, and cool to room temperature (15-30 ° C).Crystallization, filtration, vacuum drying at 55±5°C, vacuum degree -0.070-0.082Mpa for 4-6h,17.27 g of parecoxib was obtained, the yield was 97.7%, and the purity was 99.9% by HPLC.

References:

Kunyao Group Co., Ltd.;Xi Liang;Zhu Changcheng;Jin Yi;Ba Dewei;Wen Na;Hu Yanchao CN110256370, 2019, A Location in patent:Paragraph 0043; 0048-0049; 0052; 0057-0058; 0061; 0066-0067

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