Study On The Synthesis Technology Of Amino Acid Esters By Ionic Liquids

Ionic liquid is composed of ions entirely. In recent years, due to its excellent physical and chemical properties, such as non-volatile, non-flammable,heat-stable, relatively wide electrochem-ical window, and show good solubility to many inorganic and organic substances exc., room temperature ionic liquid, as a new type of green solvent, has been successfully used in organic synthesis, catalysis, electrochemistry, extraction and separation science and so on. Amino acid esters have a wide range of applications in production and life, and its Synthesis Technology has rapidly become a new research field. There are few domestic researches on Ionic liquids catalyst amino acid esters methods.Eleven kinds of acidic ionic liquids, [ePy][Br],[emim][Br],[ePy][HSO4],[Py][HSO4],[Hmim][HSO4],[ePy] [CF3COO],[Py][CF3COO],[Hmim][CF3COO],[ePy][NO3],[Hmim][TsO],[emim][BF4] were synthesized in this paper. And the structures of the novel acidic ionic liquids were characterized by IR. All of the eleven kinds of prepared Ionic liquids were used to catalytic synthesis phenylalanine n-butyl ester respectively, of which these the [Py][HSO4] have the best effects. The influentical factors have been studied and optimized. And they were further explored to form a better synthesis condition through experiments. And the mechanism of esterifition of amino acid using acidic ionic liquids as catalyst has been primarily dicussed. Eight kinds of different amino acid esters have been synthesized by direct esterification with [Py][HSO4]as catalyst which is the most effective of eleven acidic ionic liquids. Final products have been characterized by IR,1HNMR. And the differences of reaction condition and the yield of esterification on the synthesis of various amino acid ester have been analyzed. Microwave irridation has been introduced instead of traditional heating in the synthesis of Free phenylalanine isopropyl ester. Theses two technologies have been analyzed summarized.