Condensation Of Aldehydes And Ketones Catalyzed By Environmentally Friendly Bases

P-tert-butylcalix[4],[6],[8]arenes were synthesized from p-tert-butyl phenol and formaldehyde under alkaline conditions,the corresponding calix[4],[6],[8]aromatics were prepared by the dealkylation reaction using anhydrous Al Cl₃as catalyst.Then two kinds of calixarene reacted with strong base to obtain calixarene phenolate salts.The results showed that 5.0 g p-tert-butylcalix[4]arenes,20 m L of 15%Na OH,4h in oil bath at 90?,or 0.5 h in microwave at 95?,the yield of Sodium phenolate of tert-butyl Calixarene was 93.5%,and the products were characterized by IR and ¹H NMR.The Claisen-Schmidt condensation of benzaldehyde with acetophenone catalyzed by p-tert-butylcalix[6]arene phenol sodium salt was studied.The amount of catalyst,reaction temperature,reaction time and the ratio of reactants were investigated.The results showed that the conversion of benzaldehyde reached 96.4%when the amount of benzaldehyde and acetophenone was 50 mmol,the catalyst was 0.875 mmol,the temperature was 80?and the time was 20 min.The Claisen-Schmidt condensation of benzaldehyde with acetone over p-tert-butylcalix[4]arene sodium salt as catalyst was studied.The amount of catalyst,reaction temperature,reaction time and the ratio of reactants were investigated.The results showed that the optimum reaction conditions were as follows:temperature 56?,reaction time 1 h,catalyst 2%of acetone,ratio of acetone to benzaldehyde 0.5:1,conversion of benzaldehyde 99.1%,the selectivity of dibenzylidene acetone 98.5%.The optimum reaction conditions for the synthesis of benzylidene acetone were as follows:temperature 40?,reaction time 45 min,catalyst 1.5%of acetone,ratio of acetone to benzaldehyde 1.4:1,conversion of benzaldehyde 99.5%,the selectivity of benzalacetone was 97.7%.The Michael addition reaction of chalcone with p-tert-butylcalix[6]arene sodium salt as catalyst was studied.The results showed that the addition reaction of chalcone1.04 g(5 mmol),and ethyl 3-oxobutanoate 1.9m L(15 mmol),at 80?,p-tert-butylcalix[6]arene salt 0.4 g(0.36 mmol),The conversion of chalcone was 99.2%,and the selectivity of the adduct was99.3%.