离子液体催化合成阻燃剂3-羟基苯膦酰丙酸

Synthesis of Flame Retardants 3-(Hydroxyphenylphosphinyl) Propionic Acid Catalyzed by Ionic Liquid

采用两步法合成3-羟基苯膦酰丙酸(CEPPA),即以三氯化磷与苯为原料,在离子液体三乙基苄基氯化铵氯化铝([BnEt3N]Cl-xAlCl3)催化下,合成苯膦二氯(DCPP),再用DCPP与丙烯酸合成3-羟基苯膦酰丙酸(CEPPA).确定第一步最佳反应条件为:n(三氯化磷)∶n(苯)∶n([BnEt3N]Cl-xAlCl3)=3∶1∶0.025,回流温度为72℃～76℃,反应时间为6 h,产率达81.1%;第二步通过改变反应物滴加顺序及调整反应温度,得到最佳反应条件为:n(丙烯酸)∶n(DCPP)=1.30∶1.00;滴加反应阶段,控制在70℃～80℃,反应1.5～2 h后,在90℃保温反应1 h;水解反应阶段,控制在92℃～95℃反应4 h,CEPPA的产率可达91%,并解决了反应中易结块问题.

3-(hydroxyphenylphosphinyl) propionic acid(CEPPA) was synthesized by a two-step procedure: Phenyl phosphonic dichloride(DCPP) was first synthesized using phosphorus trichloride and benzene as raw materials,and triethyl benzyl ammonium chloride-aluminum chloride([BnEt3N]Cl-xAlCl3)as catalyst.The optimum conditions for the first step are as follows:n(PCl3)∶n(C6H6)∶n([BnEt3N]Cl-xAlCl3)=3∶1∶0.025,At the reflux stage,the reaction temperature was 72℃—76℃,the reaction time was 6 h,and the yield of DCPP was up to 81.1%.The optimum conditions for the second step by changing the order of the reactants and adjusting the reaction temperature were as follows: n(acrylic acid)∶n(DCPP)=1.30∶1.00;the reaction temperature was 70℃-80℃ and the reaction time was 1.5 h-2 h at the dropping stage;then reacting at 90℃ for 1 h;at the hydrolysis reaction stage,the reaction temperature was 92℃-95℃,and the reaction time was 4 h,the yield of CEPPA was up to 91%.The problem of agglomeration was easy to be solved in this procedure.