采用溶胶-凝胶法制备H3PW6Mo6O40/SiO2催化剂,以苯甲醛,乙酰乙酸乙酯和尿素为原料,无水乙醇为溶剂催化合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮,研究结果表明:反应物的摩尔比、反应温度、催化剂用量和反应时间是影响4-苯基-6...采用溶胶-凝胶法制备H3PW6Mo6O40/SiO2催化剂,以苯甲醛,乙酰乙酸乙酯和尿素为原料,无水乙醇为溶剂催化合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮,研究结果表明:反应物的摩尔比、反应温度、催化剂用量和反应时间是影响4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮合成收率的重要因素.当n(苯甲醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1.0∶1.2∶1.5,反应温度为90℃,催化剂的用量占反应物料总质量的1.5%,反应时间为75min时,产品收率可达70.3%.通过熔点、IR、1 H NMR和MS对合成目标化合物进行了表征确认.展开更多
A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m(PAn): m(HaSiW6Mo6On.) was 1...A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m(PAn): m(HaSiW6Mo6On.) was 1:1.25, volume of methanol was 20 mL, and the reflux reaction time was 2h. The structural identity of Keggin units was preserved after the incorporation into polyaniline matrix. H4SiW6Mo6040/PAn was used as catalyst in catalytic synthesis of acetals and ketals. Effects of n(aldehyde(ketone )): n(glycol), catalyst dosage and reaction time on yield were investingated. Optimal conditions were: n(aldehyde(ketone)): n(glycol)=1.0: 1.5; mass fraction of catalyst to reactants, 0.5%; reaction time, 1.0 h and cyclohexane as water-stripped reagent, 15 mL. Under these conditions, yields of actels and ketals were 31.9%-91.6%.展开更多
文摘采用溶胶-凝胶法制备H3PW6Mo6O40/SiO2催化剂,以苯甲醛,乙酰乙酸乙酯和尿素为原料,无水乙醇为溶剂催化合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮,研究结果表明:反应物的摩尔比、反应温度、催化剂用量和反应时间是影响4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮合成收率的重要因素.当n(苯甲醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1.0∶1.2∶1.5,反应温度为90℃,催化剂的用量占反应物料总质量的1.5%,反应时间为75min时,产品收率可达70.3%.通过熔点、IR、1 H NMR和MS对合成目标化合物进行了表征确认.
文摘A new environmental friendly catalyst, HaSiWrMo6O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. The optimum conditions have been found, that was, mass ratio of m(PAn): m(HaSiW6Mo6On.) was 1:1.25, volume of methanol was 20 mL, and the reflux reaction time was 2h. The structural identity of Keggin units was preserved after the incorporation into polyaniline matrix. H4SiW6Mo6040/PAn was used as catalyst in catalytic synthesis of acetals and ketals. Effects of n(aldehyde(ketone )): n(glycol), catalyst dosage and reaction time on yield were investingated. Optimal conditions were: n(aldehyde(ketone)): n(glycol)=1.0: 1.5; mass fraction of catalyst to reactants, 0.5%; reaction time, 1.0 h and cyclohexane as water-stripped reagent, 15 mL. Under these conditions, yields of actels and ketals were 31.9%-91.6%.