本研究报道了经Ritter反应合成路线的改进方法制备2-丙烯酰胺基-2-甲基丙膦酸(AMPP)阻垢剂单体.合成路线以五氯化磷出发,在甲苯溶剂中吸收异丁烯后,采用二氧化硫脱氯,得到膦酰二氯异构混合物(产率为83.3%);膦酰二氯异构混合物经室温水解,得到水解混合物(产率为99%);后者再与丙烯腈、水在浓硫酸催化下发生Ritter反应,制得了AMPP(产率为72%).研究比较了不同溶剂、脱氯剂、温度、时间、Ritter反应中的投料比等对相应产物产率的影响,并简要探讨了Ritter加成反应的机理.优化结果表明采用经Ritter反应的改进合成路线,可成功制得AMPP,三步反应总产率为59%,优于其他文献报道结果.

An improved synthesis of monomer AMPP(2-acrylamido-2-methylpropanephosphonic acid)used for scaleinhibitor is prepared based on Ritter reaction.Phosphorus pentachloride as a starting material suspended in toluene is treated with is obutene,subsequently is dechlorized by the introduction of sulfur dioxide to produce dichloride isomers with a yield of 83.3%;The dichloride isomers are easily hydrolyzed to give 99% yield of corresponding hydrolysates;the latter,acrylonitrile and water reacts together in the presence of sulphuric acid(98%)catalysis to form AMPP,72% yield.Different solvents,dechlorization agents,temperature,time,reactants ratio through Ritter addition reaction,etc and their influences on relevant yields have been investigated,and the Ritter addition mechanism has also been discussed.The optimized results indicate that AMPP is prepared successfully by employing the improved synthesis through Ritter reaction ,and the overall yield is up to 59%,superior to those reported previously.