ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of ethyl-6-aminohexanoate from caprolactam and ethanol in near-critical water

Zhi Qiang Hou, Li Gang Luo, Chun Ze Liu, Yuan Yuan Wang, and Li Yi Dai

Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, 200062, Shanghai, China

E-mail: yywang@chem.ecnu.edu.cn

Abstract: The reaction between caprolactam and ethanol was performed in near-critical water. The primary product (ethyl-6-aminohexanoate) was identified by GC-MS. The influences of the reaction temperature, residence time, initial ratio (reactant/water), pH, and additives on the yields of ethyl-6-aminohexanoate are discussed. The results showed that the yield of ethyl-6-aminohexanoate could be as high as 98 % with SnCl₂ as an additive in near-critical water. At the same time, the reaction between caprolactam and ethanol was estimated by a lumped kinetic equation as a second-order reaction in near-critical water, and the activation energy was evaluated according to the Arrhenius equation under acidic and basic conditions. Based on the results, the reaction mechanism between caprolactam and ethanol in near-critical water is proposed.

Keywords: near-critical water – caprolactam – ethanol – ethyl-6-aminohexanoate – kinetics – mechanism

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0433-6

Chemical Papers 68 (2) 164–169 (2014)