甲基丙烯醛的合成

Synthesis of Methacrolein

通过甲醛、丙醛和二乙胺的Mannich反应及Mannich碱的分解反应两步法合成了甲基丙烯醛。确定了适宜的反应工艺条件:原料n(甲醛)∶n(丙醛)∶n(二乙胺)为1.1∶1.0∶1.0,反应时间为50min,Mannich反应温度为46℃,分解反应温度为75℃。在此条件下,丙醛转化率99.8%,甲基丙烯醛收率91.2%。并对产品进行了红外光谱表征。

Methacrolein （MAL）was synthesized by two-steps process, which includes Mannich reaction of formaldehyde, propionaldehyde and diethyl amine in the presence of acid catalyst and decomposition reaction of Mannich base. The proper reaction conditions were the molar ratio of formaldehyde to propionaldehyde to diethyl amine is 1.1 ： 1.0 ＂ 1.0, reaction time is 50 min, Mannich reaction temperature is 46 ℃, decomposition temperature is 75 ℃. Under the above conditions, conversion of propionaldehyde and yield of MAL were up to 99.8% and 91.2% respectively. The product was characterized by IR spectra.