Synthesis Of β-D-GLUCOPYRANOSYL Imidazole Ring Thiohydantoins Derivatives

Glycosyl isothiocyanates as a kind of special carbohydrates,not only has good physiological function, but also is an important intermediate of organic synthesis. And alkyl or aromatic isothiocyanates, as can occur nucleophilic addition and cycloaddition reactions etc. They have been widely used for synthesis of biological activity and potential efficacy of guanidine glycosides, glycosyl thioureas, glycosyl heterocyclic compounds, as well as sugar derivatives of glycosyl amino acids, sugar-protein and protein peptide so on . The purpose of our work is to glycosyl isothiocyanate with the modified amino acids, forming a new class of thiourea, giving full the activity of two types of molecular characteristics, so that together playing a role in biological activity and would be likely to receive a new class of polysaccharide drug.This essay is mainly studied in synthesis of glycosyl isothiocyanates and further synthesis of pyranoid thiohydantoins. The glucose which is easy to obtain as raw material, the intermediate of the all acylation glucoyranosyl isothiocyanate was synthesized through two steps reaction of whole acylation and end group isothiocyanate. And then make the all acylation glucopyranosyl isothiocyanate and the glycine methyl ester muriate, the alanin methyl ester muriate, the amino-isovaleric acid methyl ester muriate, the phenylalanine methyl ester muriate, the leucine methyl ester muriate, the isoleucine methyl ester muriate, the methionine methyl ester muriate, the cysteine methyl ester muriate and so on eight kind of amino acid methyl ester class carry on the nucleophilic addition to obtain in the sugar base volute second grade the acid radical thiourea class compound. Results, a total of 18 target compounds were synthesized through the experiment. Among of them, eight pyranoid thiohydantoin compounds of 4a ~ 4h have not been reported in the literature. These compounds were characterized by infrared spectrum (IR), nuclear magnetic resonance spectra of hydrogen (1HNMR) and high-resolution mass spectrometry (ESI-MS) identification and characterization of the structure and conduct of the melting point, part of the target compounds physiological activity test is under way. Paper not only draws on the classic separation of the method of synthesis and integration of the innovations to be explored by many experiments in the process of innovation aremainly the following points:First, In the glycosyl isothiocyanate synthesis, different from the traditional method of separation of process improvement and product separation method, the direct use of multiple re-crystallization process is simple not only improve the yield, but also avoids the separation of column chromatography the process cumbersome and solvent waste.Second, Aliphatic and aromatic amino acid methyl ester with the cyclic reaction has been studied, but their response to sugar-based reports for the rare few. Therefore, amino acid ester of sugar and glucose into the ring isothiocyanate situation and amino acid esters of aliphatic and aromatic isothiocyanates were compared.Thirdly, the glycosyl isothiocyanate reactants with a variety of different conditions in the formation of a variety of heterocyclic reaction as a reference, study and amino acid ester cyclization.Fourth,try to the different resolver system synthesis of 2,3,4,6-Tetra-O-acetyl-β-D-Gluco pyranoid thiohydantoins and to find the most optimal reaction system.