Study On Green Synthetic Methodologies For Cyanohydrin Derivatives

Cyanating reactinon, a very significant organic reactinon which introduces cyano into organic molecules, is an important method for synthesis of organic intermediates. Many organic intermediates, such as nitrile cyanohydrin,α-amino-nitriles.α-amino acid,α-hydroxy acid, acyl nitrile and so on also can be synthesed by this way. It is a significant method for synthesis of chiral organic compounds and has a considerable application in organic chemistry, medicine, pesticide, dying, pigments, crystal materials and polymer materials.This paper, from the principle of green chemistry, seeks for an efficient green cyanide agent to replace traditional metal cyanide agents which are poisonous and harmful. Finally, the paper use environmentally benign potassium ferrocyanide as cyanating agent and a simple and efficient one-pot method has been developed for synthesis of cyanohydrin derivatives andα-aminonitrile.The paper is divided into three chapters:Chapter one: Research progress of organic cyanation reactionsThis chapter mainly summarize application of different cyanide agents in organic cyanation reaction, mainly intrduced HCN, metal cyanide, TMS-CN, methylcarbamate, cyanohydrins, dicyanoimidazole, acetyl cyanide and so on. This cyanide agents have been used substitution reaction, including aromatic, substitution reaction of aromatic chloride, sythesis of aminonitriles and cyanohydrin derivatives, and makes a comparison between traditional agents including potassium cyanide, sodium cyanide, related derivatives and green agents. The research result is that traditional agents generally have toxicity and can be harmful to human and environment in origin, however, the present envirornmentally benign agents potassium hexacyanoferrate(Ⅱ), which can replace the traditional and poisonous agents and make the reaction safer and more environment-friendly. The application of efficient and green agents is a hot topic of future organic cyanation reaction. Chapter two: study on synthesis of cyanohydrin derivatives with environmentally benign potassium hexacyanoferrate(Ⅱ)The study aims to make cyanohydrin derivatives from potassium hexacyanoferrate(Ⅱ), acyl chloride and aldehydes by one–pot procedure, with environmentally benign potassium hexacyanoferrate(Ⅱ) as agent, PEG-400, Pd(OAc)2 and triethylamine as catalyst. The synthetic methodology is simple and easy, having a good effect on aliphatic, aromatic and heteroaroyl. Furthermore, it has the advantages of using nontoxic potassium hexacyanoferrate(Ⅱ) as cyanide agent, solvent free and one–pot compared with traditional method. In the process of experiment, it dosen't need to separate intermediates, which matches the principles of green chemistry.Chapter three: Research on synthesis ofα-aminonitrile with environmentally benign potassium hexacyanoferrate(Ⅱ) as agentThis part makes a research on synthesis ofα-aminonitrile using different catalyst and solvent in one–pot way with environmentally benign potassium hexacyanoferrate(Ⅱ) as cyanide agent, The result shows the products are all intermediate(Schiff's bases) by heating, however, It produces a different substance from aldehydes, amine and potassium hexacyanoferrate(Ⅱ) by one–pot method in microwave, using DMF-CH3CN as solvent and NaHSO3- PEG400- Pd(OAc)2 as catalyst. Spectrum analysis shows that the target product hydrolyzed to amide. Thus, we believe it needs a further research to produceα-aminonitrile and to realize the synthesis of target product.