Study On Nucleophilic Substitution Reaction Using Acetone Cyananol As Cyanogen Source

C-X（X=OH or Cl,Br,I,etc.）bond cyano substitution reaction is an important method to introduce cyano in the molecule,but the cyanation reagents used for cyanation reaction are mostly highly toxic substances,such as Sodium cyanide,potassium cyanide,cuprous cyanide,zinc cyanide,and trimethyl cyanosilane,etc.Therefore,the search for low-toxic,environmentally-friendly sources of cyanide is a research hotspot for such reactions.In this paper,acetone cyanohydrin was used as a cyanation reagent.The cyano substitution reactions of fatty alcohols and haloalkanes were studied separately.The specific research content is as follows:1. The cyano substitution reaction of fatty alcohols.First,the reaction between 3-butyne-1-ol and acetone cyanohydrin was used as a model,and the effects of factors such as catalyst,type and amount of solvent,acetone cyanohydrin feed ratio,reaction temperature,and time on the reaction were studied,and the optimal process was established.condition.The results showed that 3-butyn-1-ol can synthesize 4-cyano-1-butyne after esterification and acetone cyanohydrin two-step nucleophilic substitution reaction.It was experimentally determined that p-toluenesulfonyl chloride was used as the acylating agent in the esterification reaction,triethylamine and 4-dimethylaminopyridine were used as the composite catalyst,THF was used as the solvent,and the reaction yield was95%at room temperature.In the cyanation substitution reaction,lithium hydroxide monohydrate was selected as the acid binding agent.The equivalent ratio of acetone cyanohydrin:Li OH·H₂O:3-butynol p-toluenesulfonate was1.6:1.6:1,and DMI and THF（volume ratio was 1:2）.As a solvent,the optimal reaction temperature is 60℃,the reaction is performed for 3.5 hours,and the yield is 93.0%.2. Universality study of the above model reactions:Diphenylmethanol,4-phenyl-2-butanol,DL-1 phenethyl alcohol,benzyl alcohol,DL-2 phenethyl alcohol,3-phenylpropanol,and n-butyl alcohol Alcohols are used as raw materials,and cyano compounds are synthesized in 70.0-95.0%yields through esterification and cyano substitution reactions.The results show that the synthetic route has good applicability to different kinds of primary and secondary alcohols.3. The pilot-scale reaction process of 3-butyne-1-ol and acetone cyanohydrin was investigated:the laboratory pilot process was used for pilot scale-up experiments,and the product’s post-processing method was changed from column chromatography to vacuum distillation.Design a rectification column with a diameter of 50 mm and an effective height of 1,000 mm was used.The stainless steel West Tower ring was used as a filler.After optimizing the process,the yield of 4-cyano-1-butyne is 89.0%,and the purity is greater than 98.0%.4. Haloalkyl cyano substitution reaction.First,the nucleophilic substitution reaction between benzyl bromide and acetone cyanohydrin was used as a model.The effects of factors such as the type and amount of catalyst and reaction solvent,the ratio of acetone cyanohydrin to the substrate,and the reaction temperature on the reaction were determined.The conditions are as follows:THF and DMI（volume ratio of 3:1）are used as solvents,lithium hydroxide monohydrate is used as acid binding agent,and the ratio of benzyl bromide:acetone cyanohydrin:lithium hydroxide monohydrate is 1:1.5:1.5,at 50℃After 3 hours of reaction,the yield was 98.0%.5. The universality study of the above model reaction:chloroalkane,bromoalkane,and iodoalkane were used as raw materials,and cyano compounds were synthesized through cyano nucleophilic substitution reaction to yield70.6-99.0%.The research results show that the cyanation substitution reaction route is suitable for different types of haloalkanes and has a wide range of universality.