204455-18-5Relevant academic research and scientific papers
Enantioselective inclusion of pyrene-1-sulfonate salts of α-amino acids with crystals of α-cyclodextrin
Hattori, Tetsutaro,Kitamoto, Yuichi,Maeda, Tetsuya,Miyoshi, Ikuko,Morohashi, Naoya
, (2020)
Enantioselective inclusion of α-amino acids with crystals of α-cyclodextrin (α-CD) has been achieved by converting the amino acids into sulfonate salts with pyrene-1-sulfonic acid (PyS). For example, crystals of α-CD selectively include L-leucine/PyS (1:1) salt in a host/guest ratio of ～1 with 92%ee from a solution of the racemic salt in ethanol/N-methylformamide (91:9) at 40 °C. Under conditions optimized for individual amino acids, the PyS salts of valine, phenylalanine, and methionine are also included with good enantioselectivities (up to 86%ee). Mechanistic studies for the inclusion of leucine/PyS salt reveals that the enantioselectivity originates from the difference in stability between the inclusion complexes of D- and L-leucine/PyS salts with α-CD in crystals.
A method for preparing DL-leucine (by machine translation)
-
Paragraph 0010, (2017/03/14)
The invention discloses a method for preparing DL-leucine. The method of the invention first through ethanol, acetamide, ethanol sodium and isobutyl bromide reaction, reaction solution distillation recovery ethanol, distillation residues hot-melt, filtering, cooling to crystallize, shall be 2-isobutyl-acetamide; and then the 2-isobutyl-acetamide react with sodium hypochlorite, reaction solution distillation recovery chcl, distillation residual the toluene-P-sulfonic acid reaction, the reaction liquid filtering, cooling to crystallize, shall be leucine paratoluene sulfonic acid; leucines toluene-P-sulfonic acid with sodium hydroxide reaction, and the re-adjustment to pH 6-6.5 DL-leucine can be obtained. The invention chemical synthetic mild reaction conditions, the low requirements for the equipment, production cycle is short, with little investment, low cost; relatively high yield, there are few by-products, can be produced in large quantities, which is beneficial for industrial; acetamide can be formed by preparing ketene dimer, easily available raw materials. (by machine translation)
