位点可控的二乙氧磷酰化壳寡糖的合成

Site-Controlled Synthesis and the Optimum Reaction Conditions of Diethoxy Phosphoryl Chitooligosaccharides

以壳寡糖(COS)为原料,二乙基亚磷酸酯(DEPH)为磷酰化试剂,通过改变反应体系中三乙胺(TEA)的用量控制二乙基磷酰基的进攻位点,实现了2-N和3,6-O位点二乙基亚磷酰化壳寡糖衍生物的合成,制备了N-二乙氧磷酰化壳寡糖及N,O,O-二乙氧磷酰化壳寡糖,并采用单一变量法对合成条件进行了优化,用31P NMR对产物进行了跟踪分析.合成N-二乙氧磷酰化壳寡糖的最优反应条件为2 g COS,nCOS∶nTEA=1∶6,nCOS∶nDEPH=1∶3,滴加DEPH和CCl4的时间为2 h,低温反应2 h,在该优化条件下产物的磷含量为1.50%(质量分数).合成N,O,O-二乙氧磷酰化壳寡糖的最优反应条件为2 g COS,nCOS∶nTEA=1∶6,nCOS∶nDEPH=1∶5,滴加DEPH和CCl4的时间2 h,低温反应4 h,常温反应8 h,在该优化条件下产物的磷含量为3.42%.对合成反应的可能机理进行了推测.

Using low molecular weight chitooligosaccharide and dialkyl phosphite as raw materials,the site-controlled diethoxy phosphoryl chitooligosaccharides were synthesized through varying the amount of triethlamine.Then,N-diethoxy phosphoryl chitooligosaccharide and N,O,O-diethoxy phosphoryl chitooligosaccharide were obtained.The optimal synthetic conditions were studied by the single factor variable method.And the optimum reaction conditions of N-diethoxy phosphoryl chitooligosaccharide were as follows： 2 g COS,nCOS∶ nTEA=1∶ 6,nCOS∶ nDEPH=1∶ 3,2 h for the time of dropwise for the solution of DEPH in CCl4,2 h for the time at the low temperature.The maximum phosphorus content achieves 1.50% under the optimum conditions.The optimum reaction conditions of N,O,O-diethoxy phosphoryl chitooligosaccharide were as follows： 2 g COS,nCOS∶ nTEA=1∶ 6,nCOS∶ nDEPH=1∶ 5,2 h for the time of dropwise for the solution of DEPH in CCl4,4 h for the time at the low temperature,8 h for the reaction time at the room temperature.The maximum phosphorus content achieves 3.42% under the optimum conditions.Moreover,a possible reaction mechanism was proposed to explain the formation of diethoxy phosphoryl chitooligosaccharides.