| 摘要 |
Piroxicam drug intermediates 3-oxo- 1,2-benzisothiazole- 1,1 -dioxide-2-acetate synthesis method, comprising the following steps: equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, the reaction vessel was added 2.16mol saccharin amine (2), 2.1-2.3L nitromethane, controlling the stirring speed 160-190rpm, raised solution temperature to 110-115 0C, slowly added 2.3-2.5mol ethyl acetate (3), continued stirring for 11-13h, distilled off most nitromethane, the reaction solution was poured into potassium chloride solution, filtration, got a white solid, recrystallized from 900ml propionitrile solution, reducing the solution temperature to 3 - 5 0C, standing for 30-36h, suction filtered, washed with toluene solution, dehydration with dehydrating agent, got 3-oxo- 1,2-benzisothiazole- 1,1 -dioxide-2-acetate. |
