Phosphoric acid tris-di:methyl-amide prodn. - by reaction of di:methyl:amine with phosphorus oxy:chloride-HMPA complex in HMPA as solvent

摘要

In a new process for the prodn. of phosphoric acid tris (dimethylamide) (I) by reaction of POCl3 with at least 6 molar proportions of dimethylamine under anhydrous conditions in the presence of excess (I) as liq. diluent, (A) the dimethylamine is added to a mixt. consisting of the 1:1 complex of POCl3 and (I) and of (I) as reaction medium while maintaining a reaction temp. of 50-170 deg., and (B) (I) is subsequently sepd. from the reaction mixt. in a conventional manner. In a pref. procedure, dimethylamine is added to a soln. of the complex cpd. in 0.7 to 2 times its wt. of (I) while maintaining a temp. of at least 100 deg.C. The addn. is advantageously carried out in a closed system under reduced pressure. (I) (also known as hexamethyl phosphortriamide or HMPA) is useful as a polar aprotic solvent and reaction medium with catalytic properties. It is also useful as an intermediate for pesticides.