| 摘要 |
Antitussive drug intermediates benzyl acetone synthesis method comprising the following steps: equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, the reaction vessel was added 320ml cyclohexane solution, added in batches 1.3mol stannous chloride, added 2.3mol ethyl acetoacetate (1) , controlling stirring speed 130-160rpm, continued the reaction for 60-90min, the solution temperature was raised to 65-70 C, refluxed for 3-5 h, added dropwise 2.6-2.8 mol benzylamine (3), controlled the dropwise addition time for 3-4h, the reaction was refluxed for 3-4h, yielded the intermediate (4), reducing the solution temperature to 10 - 15 C, added 330ml potassium bisulfite solution, maintained reflux to 4-5h, generating oil, oxalic acid solution was added to adjust the pH to 4-5, continued reflux for 4-6 h, vacuum distillation, collecting distillate of 95--105 C, washed with salt solution, washed with acetonitrile solution, recrystallized from nitromethane solution, got crystals of benzyl acetone . |
