The selective phosphylation of ethanolamine

In nonaqueous solvents under conditions where phosphylation of either of the functional groups of ethanolamine can occur, it is found that phosphofluoridates react exclusively with the hydroxyl group. This O-phosphylation appears to be specific for phosphofluoridates, since phosphochloridates, tetraethyl pyrophosphate, and ethyl N,N-dimethylphosphoramidocyanidate react predominantly with the amino moiety. However, with these compounds the reaction is not as specific, some O-phosphylation being observed, especially with the last compound. Possible reasons for this difference in behavior are discussed.