Study On Synthesis Of Cyanohydrin Derivatives From Potassium Ferrocyanide,an Environmentally Friendly Cyanide Agent

Organic cyanation reaction is a very important organic synthesis reaction,many important organic intermediates such as:nitrile,cyanol,aminonitrile,α-amino acid,α-hydroxy acid,α-keto acid,acyl nitrile can be synthesized by organic cyanation reaction.At the same time,cyanation reaction is also an important way to synthesize chiral organic compounds,so it has a very important application in organic chemical industry,medicine,pesticide,dye,pigment,liquid crystal materials,polymer materials and other industries.At present,the most commonly used cyanide agents for organic cyanide reactions are hydrocyanic acid（HCN）,metal cyanide（such as:NaCN,KCN,CuCN,Ni（CN）₂,Zn（CN）₂,etc.）and trimethylsilane cyanide（TMS-CN）.However,these cyanide agents are highly toxic,unsafe to use and environmentally unfriendly.Potassium ferrocyanide is a by-product of the coal chemical industry.It does not need to be made from highly toxic cyanide and is a co-organism in coal processing.In particular,it is not toxic or harmful,and can even be used as an auxiliary additive in edible salt.Therefore,if potassium ferrocyanide can be used as a cyanide agent for organic cyanidation reaction,it will be a very environment-friendly improvement.This paper reviews the research progress and types of conventional cyanide reagents and potassium ferrocyanide in organic cyanide reactions.Four kinds of cyanol derivatives were synthesized from potassium ferricyanide as an environmentally friendly cyanide agent and aryl chloride as starting material in a pot under different conditions.They are aryl methyl cyano-aryl formates（Yield of 61.7%⁸0.3%）,α-amino-α-cyano-arylacetate（Yield of 48.8%⁶4.2%）,2-aryl-（2’,2’-dichloro-1’-aryl-vinyl oxide）acetonitrile（Yield of 43.1%⁶6.8%）,aryl formic acid-1,1-dicyanoyl methyl ester（Yield of 69.8%⁸4.2%）.The effects of the ratio of raw materials,the reaction solvent,the reaction time,the reaction temperature and other factors on the yield of the cyanol derivatives were studied,and the optimum reaction conditions were determined.The mechanism of synthesis of cyanol derivative aryl methyl cyanate and 2-aryl-（2’,2’-dichloro-1’-aryl-vinyl oxide）acetonitrile and aryl formic acid-1,1-dicyanoyl methyl ester were explained.The structures of all compounds of the tetrahydrocyanol derivatives were confirmed by IR,¹H NMR,¹³C NMR and elemental analysis.The method has the characteristics of simple operation,mild reaction,green environment protection and high yield.It provides the experimental basis for the industrial production of these cyanol derivatives.