| abstract |
This invention relates to the preparation of cyclic urea compounds. More specifically, this invention is directed to methods for selectively alkylating diamines, methods for selectively converting a mixture of alkylated and non-alkylated diamines to cyclic urea compounds, methods to purify cyclic urea compounds having a single N-substitution, methods to convert a cyclic urea compound having a single N-substitution to a cyclic urea compound having either symmetrical or non-symmetrical N,N'-disubstitution, and methods to remove protecting groups from cyclic urea compounds. |