Preparation method of parecoxib sodium impurity
A technology of parecoxib sodium and impurities, applied in the direction of organic chemistry, etc., can solve problems such as shortage, and achieve the effects of improving product quality, easy access to raw materials, and simple operation
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0049] Preparation of step 1, 5-methyl-4-phenylisoxazole-3-boronic acid (Ⅳ)
[0050] Put 3-bromo-5-methyl-4-phenylisoxazole (10g, 42mmol) into the reaction flask, add 100ml of tetrahydrofuran, protect with high-purity nitrogen, stir, cool down to -70°C, and then dropwise add 2.5M normal Butyllithium n-hexane solution (18.5ml, 46.25mmol), react for about 1.5hr, add triisopropyl borate (16.6g, 88.25mmol) dropwise at around -70°C, after the dropwise completion, react for 30min, then slowly heat up to At room temperature, react for about 4 hours, cool down to about -10°C, slowly add 50ml of water dropwise, after the drop is complete, adjust the pH to 2-3 with 6mol / L hydrochloric acid aqueous solution, extract with ethyl acetate, wash with saturated saline, dry over magnesium sulfate, filter, Concentrate and crystallize to obtain compound IV (4.3 g, yield 59.87%).
[0051] The preparation of step 2, 4-(5-methyl-4-phenyl-3-isoxazole) benzenesulfonamide (Ⅱ)
[0052] Compound IV (5g...
Embodiment 2
[0081] Preparation of N-﹝4-(5-methyl-4-phenylisoxazol-3-yl)benzenesulfonyl﹞propanamide
[0082] Put compound II (5g, 15.9mmol) into a round-bottomed flask, then add 50ml of tetrahydrofuran, 0.5g of 4-dimethylaminopyridine, 10ml of triethylamine, stir, control the temperature at -5~0°C, add propionic anhydride (5ml, 38.4mmol), the dropwise addition was completed, and the temperature was slowly raised to about 35°C, reacted for 4 to 5 hours, monitored by TLC, until the end of the reaction, the reaction time was about 16 hours, the reaction solution was poured into ice water, dichloromethane extracted, 3mol / Washed with L hydrochloric acid, dried over sodium sulfate, filtered, concentrated, and the crude product was dissolved and crystallized in 50ml of methanol for purification to obtain the target compound I as a white crystalline powder (5.4g, 14.6mmol). TLC conditions: dichloromethane:methanol:concentrated ammonia water=90:10 :0.5 (volume ratio). Yield 95.1%; HPLC purity: 99...
Embodiment 3
[0084] Preparation of N-﹝4-(5-methyl-4-phenylisoxazol-3-yl)benzenesulfonyl﹞propanamide
[0085] Put compound II (5g, 15.9mmol) into a round bottom flask, then add 50ml of tetrahydrofuran, 0.5g of 4-dimethylaminopyridine, 15ml of triethylamine, stir, control the temperature at -5~0°C, add propionic anhydride (10ml, 76.8mmol), the dropwise addition was completed, and the temperature was slowly raised to about 40°C, and the reaction was carried out for 4 to 5 hours (hr), monitored by TLC until the end of the reaction, the reaction time was about 8 hours, the reaction solution was poured into ice water, extracted with dichloromethane , washed with 3mol / L hydrochloric acid, dried over sodium sulfate, filtered, concentrated, and the crude product was dissolved and crystallized in 50ml of methanol for purification to obtain the target compound I white crystalline powder (5.5g, 14.8mmol), TLC conditions: dichloromethane: methanol: concentrated ammonia water = 90:10:0.5 (volume ratio)....
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 


