1115-47-5Relevant articles and documents
Rhodium-catalysed racemisation of N-acyl α-amino acids
Hateley, Martin J.,Schichl, Daniel A.,Kreuzfeld, Hans-J?rn,Beller, Matthias
, p. 3821 - 3824 (2000)
The first transition metal-catalysed racemisation of N-acyl α-amino acids, which is of importance for kinetic resolution processes, is described. Enantiomerically pure N-acyl α-amino acids were efficiently racemised under mild conditions using various rhodium complexes as catalysts, e.g. [Rh(cod)Cl]2, in the presence of phosphines. (C) 2000 Elsevier Science Ltd.
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Wheeler,Ingersoll
, p. 4604 (1951)
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Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
supporting information, (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Synthesis method for organic synthesis of intermediate N-acetyl-DL-methionine
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Paragraph 0006; 0014; 0015, (2018/07/30)
The invention relates to a synthesis method for organic synthesis of an intermediate N-acetyl-DL-methionine. The method mainly includes the steps of: adding 3mol DL-methionine into 4-5mol 4-bromo-acetanilide for heating dissolution, adding 4-5mol bromoethylamine, conducting reflux for 90-120min, adding a 300ml ethanol solution, carrying out concentration and evaporation to dryness, lowering the temperature of the residue to 10-15DEG C, performing washing with a toluene solution, conducting washing with a nitroethane solution, conducting recrystallization in a butanol solution, and performing dehydration with a dehydrant, thus obtaining the finished product N-acetyl-DL-methionine.
Separation and purification method for N-acetyl-D, L-methionine
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Paragraph 0037-0041, (2017/06/08)
The invention discloses a separation and purification method for N-acetyl-D, L-methionine. The method comprises the steps of 1) subjecting an acetylation reagent and methionine salt to the acetylation reaction, adjusting the pH value of the reaction solution to be 3-5 by using an acidifying agent, maintaining the temperature of the reaction solution to be 50 DEG C-75 DEG C, and subjecting the reaction solution to the decoloration treatment; 2) adopting water as an eluent, subjecting the decolored reaction solution to the continuous chromatographic separation treatment through a continuous chromatographic separation system to respectively obtain an N-acetyl-D, L-methionine aqueous solution and a saline solution containing sodium acetate. The method enables the high-purity separation of N-acetyl-D, L-methionine, wherein the N-acetyl-D, L-methionine is completely and effectively separated from organic salts and inorganic salts. Therefore, the usage of organic solvents, toxic and harmful to the traditional production process, is avoided. Meanwhile, the method is low in energy consumption, high in production efficiency and simple in operation. The method improves the product yield and the product purity, which is green and environmentally-friendly.
