192210-96-1Relevant academic research and scientific papers
The enzymatic resolution of 1-(4-chlorophenyl)ethylamine by Novozym 435 to prepare a novel triazolopyrimidine herbicide
Zhang, Yinjun,Cheng, Feifei,Yan, Hongde,Zheng, Jianyong,Wang, Zhao
, p. 1225 - 1232 (2018/09/25)
The kinetic resolution of (R,S)-1-(4-chlorophenyl)ethylamine was accomplished using a commercial lipase from Candida antarctica (Novozym 435). The performance of this lipase was investigated for the enantioselective amidation of (R,S)-1-(4-chlorophenyl)ethylamine, leaving the target product (S)-1-(4-chlorophenyl)ethylamine in its unreacted form. The effects of various types of solvents and an acyl donor, the molar ratio of the substrate to the acyl donor, and the reaction temperature were studied. The optimum reaction conditions were found to result in amidation with methyl 2-tetrahydrofuroate at 40°C in methyl tert-butyl ether, with a substrate/acyl donor molar ratio of 1:2.4. The conversion rate of (R,S)-1-(4-chlorophenyl)ethylamine was 52%, with an enantiomeric excess of 99% towards the unreacted substrate in a reaction time of 22?hours. Finally, using optically pure (S)-1-(4-chlorophenyl)ethylamine as the raw material, the chemical synthesis of (S)-N-(1-(4-chlorphenyl)ethyl)-2-(5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-2-ylthio)acetamide, a novel triazolopyrimidine herbicide, was achieved, and the total yield and purity were 83.5% and 95.3%, respectively.
Solvent-free kinetic resolution of primary amines catalyzed by Candida antarctica lipase B: Effect of immobilization and recycling stability
Paeivioe, Mari,Perkioe, Paeivi,Kanerva, Liisa T.
experimental part, p. 230 - 236 (2012/06/15)
Highly enantioselective (E >200) N-acylation of nine racemic primary amines with isopropyl methoxyacetate in the presence of Candida antarctica lipase B (Novozym 435) has been reported to yield the unreacted (S)-amines (ee ≥98%) and produced the (R)-amides (ee ≥95%) at 50% conversion under solvent-free conditions. One of the amines and the acyl donor have been used in an equimolar ratio at room temperature (23 °C). Under the reaction conditions, the reuse stability of Novozym 435 with 1-phenylethylamine (as a model compound) has been shown to be poor while somewhat improved stability has been observed with an in-house prepared sol-gel CAL-B catalyst.
