活性碳负载磷钨杂多酸催化合成双(4-羟基苯基)苯基甲烷

Synthesis of Bis-(4-hydroxyphenyl)phenylmethane by Using Solid Heteropolyacid PW_(12)/C as Catalyst

对以活性碳负载磷钨杂多酸为催化剂 ,巯基乙酸为助催化剂 ,苯酚和苯甲醛为原料 ,催化合成双 (4-羟基苯基 )苯基甲烷的反应进行了研究 .试验发现 ,磷钨杂多酸的活性碳负载量为 5 0 %时 ,催化活性最好 .通过对缩合反应的正交试验表明 ,活性碳负载磷钨杂多酸的负载量、主催化剂用量、助催化剂用量、酚醛物质的量比、反应的温度及反应的时间对缩合反应的收率有影响 .反应的最佳条件为 :活性碳负载磷钨杂多酸的负载量为 5 0 % ,n(酚 ) /n(醛 ) =4∶ 1 ,反应温度 1 0 0℃ ,主催化剂2 .5 g,助催化剂 0 .1 m L,反应时间 2 h,收率可达 73 .8% .

Bis-(4-hydroxyphenyl)phenylmethane is synthesized from phenol and benzaldehyde by using solid heteropolyacid PW 12/C as catalyst and thioglycolic acid as assistant catalyst. It is found that catalysis activity of solid heteropolyacid PW 12/C is the best when its adsorption amount reaches to 50%. The influences of molar ratio of phenol to benzaldehyde, reaction temperature, reaction time, catalyst dosage and assistant catalyst dosage on the Baeyer condension reaction are studied by using orthogonal design method. It is shown that the yield of the Bis-(4-hydroxyphenyl)phenylmethane reaches up to 73 8% under the optimum reaction conditions: weight ratio H 3PW 12O 40/C is 50%, molar ratio phenol/benzaldehyde is 4∶1, solid heteropolyacid catalyst is 2.5g, assistant catalyst thioglycolic acid is 0.1mL, the reaction temperature is 100℃, and reaction time is 2h. The structure of Bis-(4-hydroxyphenyl)phenylmethane is confirmed by IR.