| 摘要 |
Methenamine drug intermediates N- benzoyl glycine synthesis method, comprising the following steps: equipped with a stiffer and a dropping funnel, the reaction vessel was added 0.34 mol glycine (3), 300ml sodium sulfite solution, controlling the stirring speed 130-160rpm, slowly added dropwise 0.39-0.40mol benzamide solution (2), the stirring was continued for 80-120min, the temperature of the solution is reduced to 10 - 15 C, added 200--230ml oxalic acid solution, adjusting the pH of the solution to 5-6, allowed to stand for 8-9 h, the precipitated solid was filtered and the solid was added to 200ml dimethyl amine solution, refluxed for 30-50min, reduced the solution temperature to 5 - 8 0C, suction filtered, the filter cake was washed with dimethylamine solution, recrystallization with 700ml potassium bromide solution, molecular sieves bleaching, filtration, the solution temperature is reduced to 1-3 0C, crystals precipitation, suction filtration, dehydration with dehydrating agent, got N- benzoyl glycine. |
