| 摘要 |
Balsalazide drug intermediates nitrobenzoylhydrazone - alanine synthesis method, comprising the following steps: equipped with a stirrer, a reflux condenser and a dropping funnel, the reaction vessel was added 0.17-0.19mol sodium sulfite, 0.02-0.04mol cyclohexanol, 0.13 mol P -aminopropionic acid, 90-120ml sodium chloride solution, controlling the stirring speed 130-160rpm, dropping 0.13-0.16mol nitro-benzamide (3) dissolved in 1 10ml methylamine solution, control the dropping time in 3-4h, raised the solution temperature to 40-45 C, controlled the reaction time to 4-5h, the aqueous layer was separated, oxalic acid solution was added to adjust the solution pH to 4-5, the precipitated solid was suction filtered, washed with saline solution, dehydrated with dehydrating agent, recrystallized from ethyl acetate solution , got crystals nitrobenzoylhydrazone -0- alanine . |
