Synthesis And Characterization Of Amide Compound Containing Nitrogen And Sulfur Atoms And Their Chiral Complexes

The amide compound are broadly applied in intermediate and product of medicine, pesticide, paper making etc. The general synthetic methods of amide compound are that the first step is the synthesis of carboxylic acid derivatives, for example acyl halide, anhydride, ester, and the second step is ammonolysis reaction of these carboxylic acid derivatives. Amide compound can also be synthesized under microwave Irradiation or by enzyme catalytic reaction. As we all know, it is a traditional method that amide compound can be prepared by the salt-forming reaction, then dehydration reaction. However, the yield was very low. If the reactant is amino acid, the yield will be lower because of the decomposition of amino acid. Asymmetric catalysis has become a very important method to synthesize chiral compound in organic synthesis. The study of biological activity and synthetic method of ligand containing nitrogen and sulfur atoms and their metal complexes has been paid attention. Therefore, the research of new ligand containing nitrogen and sulfur atoms and its metal complexes will play an important part in theoretical study and practice application.In this paper, new amide compounds were designed based on the molecular structure. These amide compounds can be prepared by a simple synthetic method from L-methionine and diamine compounds (ethyl diamine, 1,6-hexamethylenediamine and Piperazine). The synthetic method involved the synthesis and dehydration of ammonium carboxylate. The key step was the high yield of ammonium carboxylate. The structures of the synthesized amide compounds were determined by 13C NMR, IR spectra and Element Composition Analysis. The optimized synthetic conditions were determined by a single factor experiment. (1) The optimum reaction condition of direct reaction method was as follows: the molar ratios of L-methionine and diamine compounds were 4:1; the solvent was ethanol; the dehydration temperature was 130℃; the dehydration time was 6 hours. The best yield of products was about 71.1wt.%, 66.7wt.%, 64.9wt.%. (2) The optimum reaction condition of diphase reaction method was as follows: the molar ratios of L-methionine and diamine compounds were 1:1; the solvent was deionzed water and chloroform; the reaction time was 8 h; the pH of separation solution was about 3; the dehydration temperature was 130℃; the dehydration time was 6 hours. The best yield of products was about 74.3 wt.%,70.2 wt.%,67.5 wt.%. Compared with traditional synthetic method, there were less reaction steps, shorter reaction time, more moderate reaction condition and higher yield for the two synthetic methods mentioned above.In this paper, the synthesized amide compounds were chiral ligands containing nitrogen and sulfur atoms, and they can constitute chiral complex with transition metal Pd. The structures of these complexes were determined by UV and IR spectra. They were six-numbered chelated ring structure with the molar ratio 1:1 of Pd and these ligands.