Microwave Irradiation Assisted Synthesis Of Calix[4]arene Imidazolium Salts And Its Application In Fluorination

Nine calix[4]arene imidazolium salts were synthesized under microwave irradiation.Also their catalytic properties in the fluorination and extraction properties of K⁺were studied.Tert-butyl calix[4]arene was synthesized using tert-butyl henol and formaldehyde as starting materials with a yield of 75.9%.O-alkylated calix[4]arene derivatives were synthesized after mcrowave irradiation for 10?15min by using calix[4]arene and bromoalkanes.The yields of reaction are between 67.4%?81.1%.Nine calix[4]arene imidazolium salts were obtained by microwave-assisted synthesis and anion complexation with yields between 53%?89.1%.The structures were confirmed by elemental analyses,IR,¹H NMR,¹⁹F NMR,³¹P NMR.The catalytic performance of nine compounds in the fluorination was studied in this paper.The results showed that these compounds possessed excellent catalytic properties of the fluorination.The yields of fluoride were between 80.9%?92.7%.The yields of reaction with varieties of reaction temperature,reaction time,amount of catalyst and the ratio of reactants were compared.With the mole ratio of p-chloronitrobenzene and SD-KF as 1:2,the amount of catalysts as 0.4%of p-chloronitrobenzene,the temperature as 190?and the reaction time as 3 hours,the yield was 92.7%.Finally these compounds'extraction properties of K⁺were evaluated.They have good extraction efficiency of K⁺.Compounds 5c has the best extraction performance.The extracted percentage was as high as 75.5%.