微波辅射树脂催化合成L-氨基酸酯的研究

Study on the Synthesis of L-amino Acid Esters Catalyzed by Resin under Microwave Irradiation

摘要:

在微波辐射下，强酸性阳离子交换树脂为催化剂，一步酯化合成了8种空间位阻较高的L-氨基酸异丙酯和异丁酯，并用1HNMR和IR对其结构进行了表征。研究结果表明，微波辐射大大加速了酯化反应，所得8种酯的酯化收率均在50~70%之间。微波辐射反应所需时间大幅缩短，仅为常规加热时间的1/48~1/72，且反应物极性越大，反应时间缩短越明显。同时，就微波辐射功率、辐射时间及加热方式对酯化反应的影响进行了研究。

Abstract:

Eight kinds of larger steric hindrance L-amino acid esters were synthesized by direct esterification of L-amino acid and isopropanol or isobutylalcohol with strong acidic cation resin as catalyst under microwave irradiation. The results showed that the esterification was greatly accelerated under microwave irradiation with 50~70% yields of these esters reached. The reaction time was substantially shorten to 1/48~1/72, especially for the reactant with higher polarity compared with conventional heating method. The structures of these esters were characterized by 1HNMR and IR. However, the influence of reaction conditions such as power, time of microwave irradiation and heating type on esterification was discussed.