Synthesis of 2-Amino-ε-caprolactam by Cyclodehydration of Lysine in Subcritical Water

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Akio Kodama²  Motonobu Goto²  Shoji Nagaoka¹  Jun Hiraki³  Shigeki Matsuda¹  Megumi Umeda²  Shigeo Masuhara³  Tsutomu Hirose² 

[1] Material Development Department, Kumamoto Industrial Research Institute;Department of Applied Chemistry and Biochemistry, Kumamoto University;Chisso Co., Ltd.

关键词: Subcritical;    Supercritical;    Water;    Lysine;    Aminocaprolactam;    Dehydrolysis;    Cyclization;   

DOI  :  10.1252/jcej.37.353

来源: Maruzen Company Ltd

【 摘 要 】

References(8)Cited-By(5)Water near the critical temperature has been focused as a novel reaction medium. We observed that nylon 6 can be easily depolymerized in sub- or supercritical water to produce ε-caprolactam in our previous work. This indicates that the cyclodehydration reaction proceeds in water near the critical temperature. In this work, we investigated synthesis of 2-aminocaprolactam from L-lysine by cyclodehydration in subcritical water. The reaction was carried out in a batch reactor (5.4 ml in volume) in a temperature range from 573 to 633 K. The reaction time was changed from 5 to 60 min to obtain kinetic data of the reaction. The reaction products were analysed by using LC-MS and HPLC (mobile phase: 0.01 N NaOH solution). As the reaction time increased, the reaction product coloured yellow more deeply. At higher temperature, an yellow or green coloured oil phase was observed. In the products, 2-aminocaprolactam was identified by LC-MS. Lysine was cyclodehydralyzed to 2-aminocaprolactam and then further reacted to by-products in subcritical water. Lysine was completely reacted in 30 min at 633 K. The highest yield of 2-aminocaprolactam was 51% in 20 min at 603 K. For a longer reaction, the yield of 2-aminocaprolactam decreased due to secondary reaction. Subcritical water was found to be an excellent reaction medium for cyclodehydration.

【 授权许可】

Unknown