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A new environmental friendly catalyst H3PW12O40/PAn was prepared and identified by means of FT-IR,XRD,and TG/DTA.The optimum conditions have been found;that is,the mass ratio of PAn to H3PW12O40 is 1:1.5,the volume of methanol is 20 mL,and the reflux reaction time is 3 h.The structural identity of Keggin units is preserved after the incorporation into polyaniline matrix.Catalytic activities of H3PW12O40/PAn in synthesizing 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,cyclohexanone ethylene ketal,cyclohexanone 1,2-propanediol ketal,butanone ethylene ketal,butanone 1,2-propanediol ketal,2-phenyl-1,3-dioxolane,4-methyl-2-phenyl-1,3-dioxolane,2-propyl-1,3-dioxolane,and 4-methyl-2-propyl-1,3-dioxolane were reported.It has been demon-strated that H3PW12O40/PAn is an excellent catalyst.Various factors concerned in these reactions were investigated.The optimum conditions are as follows:the molar ratio of aldehyde/ketone to glycol(r) is 1:1.5,the mass ratio of the catalyst used to the reactants is 0.6%,and the reaction time is 1.0 h.Under these conditions,the yield is as follows:2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,69.0%;2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,79.5%;cyclohexanone ethylene ketal,78.9%;cyclohexanone 1,2-propanediol ketal,85.3%;butanone ethylene ketal,56.9%;butanone 1,2-propanediol ketal,78.1%;2-phenyl-1,3-dioxolane,76.3%;4-methyl-2-phenyl-1,3-dioxolane,94.2%;2-propyl-1,3-dioxolane,70.7%;and 4-methyl-2-propyl-1,3-dioxolane,79.2%.
A new environmental friendly catalyst H3PW12O40 / PAn was prepared and identified by means of FT-IR, XRD, and TG / DTA. The optimum conditions have been found; that is, the mass ratio of PAn to H3PW12O40 is 1: 1.5, the volume of methanol is 20 mL and the reflux reaction time is 3 h. The structural identity of Keggin units is preserved after incorporation into polyaniline matrix. Catalytic activities of H3PW12O40 / PAn in synthesizing 2-methyl-2-ethoxycarbonylmethyl-1,3- dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, butanone 1,2-propanediol ketal, butanone 1,2-propanediol ketal, dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl- 1,3-dioxolane, and 4-methyl-2-propyl- 1,3-dioxolane were reported. It has been demon-strated that H3PW12O40 / PAn is an excellent catalyst. Important factors concerned in these reactions were investigated. The optimum conditions are as follows: the molar ratio of aldehyde / ketone to glycol (r) is 1: 1.5, t The mass ratio of the catalyst used to the reactants is 0.6%, and the reaction time is 1.0 h. In these conditions, the yield is as follows: 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 69.0%; 2 , 4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, 79.5%; cyclohexanone ethylene ketal, 78.9%; cyclohexanone 1,2-propanediol ketal, 85.3%; butanone ethylene ketal, 56.9%; butanone 1,2-propanediol ketal , 78.1%; 2-phenyl-1,3-dioxolane, 76.3%; 4-methyl-2-phenyl- 1,3-dioxolane, 94.2% methyl-2-propyl-1,3-dioxolane, 79.2%.