2-丙烯酰胺基-2-甲基丙膦酸的合成

报道了2－丙烯酰胺基－2－甲基丙膦酸的合成方法，并的制备了这一含磷阻垢剂单体，合成路线以五氯化磷出发，在甲苯溶剂中吸收异丁烯后，改进采用二氧化硫脱氯，得到膦酰二氯异构混合物（产率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99％），后者再与丙烯腈水在浓硫酸催化下发生加成反应，制得2－丙烯酰胺基－2－甲基丙膦酸这一含磷阻垢剂单体（产率72％），研究比较了不同溶剂、脱氯剂、温度、时间、加成反应中的投料比等对相应产物的影响，并探讨了加成反应的机理，优化结果表明采用二氧化硫脱氯剂的改进路线，可成功制得2－丙烯酰胺基－2－甲基丙膦酸，总产率59％, ．优于其他文献报道结果。

Synthesis of 2-acrylamido-2-methylpropanephosphonic acid

A phosphorus containing monomer used for scale inhibitor synthesis was reported and 2 acrylamido 2 methylpropanephosphonic acid was prepared accordingly in this paper. Phosphorus pentachloride suspended in toluene as a starting material was treated with isobutene, subsequently was dechlorized by the introduction of sulfur dioxide to produce dichloride isomers with yield 83.3%; the dichloride isomers were easily hydrolyzed to give 99% yield of corresponding hydrolysates; the latter,together with acrylonitrile and water reacted in the presence of sulphuric acid (98%) catalysis to form the target 2 acrylamido 2 methylpropanephosphonic acid in 72% yield. Different solvents, dechlorization agents, temperature, time, reactant ratio as well as their effects on relevant yields were investigated; meanwhile the addition mechanism was discussed. The optimized results indicated that the modified synthesis by employing dechlorization agent of sulfur dioxide gave a better overall yield 59% than those reported previously.