Study On The Catalytic Synthesis Of Several Typical Ketals And Organic Acid Esters

Ketalization reaction and esterification are two important organic reactions in chemical engineering.Concentrated sulphuric acid was the main liquid acid catalyst in traditional ketalization reaction and esterification.In recent years,solid acids are getting more and more attention in organic synthesis for their high activity,high selectivity as well as environmentally friendliness.At the same time,microwave technique has attracted many researchers for its advantages,such as short reaction time,high yields,pure products and easy workup.In this paper, the application of microwave radiation and acid catalysis on synthesis of several typical ketals and organic acid esters has been studied.The products were well characterized by refractive index analysis and IR. These works were as follows:1.The catalyzing capability of p-toluene sulphonic acid on ketalization reaction was studied using cyclohexanone,1,2-propanediol and glycol as raw materials without solvent under microwave irradiation. The effects of amount of catalyst,microwave irradiation power,reactant ratio,microwave irradiation time on the yield of cyclohexanone 1,2-propanediol ketal were systematically investigated by single factor experiments.And then,optimum reaction conditions for the synthesis of cyclohexanone glycol ketal were discussed by orthogonal experiments.2.Cyclohexanone glycol ketal was directly synthesized from cyclohexanone and glycol under microwave irradiation using ammonium ferric sulfate as the catalyst.The effects of catalyst dosage,microwave irradiation power,reactant mole ratio and microwave irradiation time on the yield of cyclohexanone glycol ketal were investigated in our experiments.3.The esterfication of benzoic acid and isobutyl alcohol was studied with activated carbon supported p-toluene sulphonic acid as heterogeneous catalyst.The effects of different factors such as catalyst dosage,mole ratio of reactants and reaction time on the yield ofisobutyl benzoate were carefully investigated.4.The esterfication of oxalic acid and butyl alcohol was studied with copper p-toluene sulfonate as catalyst and cyclohexane as water carrying agents.The effects of different factors such as catalyst dosage,mole ratio of reactants,carrying agent amount and reaction time on the yield of dibutyl oxalate were importantly investigated.5.The esterfication of oxalic acid and butyl alcohol was studied with ferric chlorid as catalyst and cyclohexane as water carrying agents. Factors influencing on the yield of dibutyl oxalate were discussed and optimum reaction conditions were found by orthogonal experiments.