Synthesis of N-Amino-Succinimides by a Multicomponent Reaction

Significance

Reported is the synthesis of N-­amino-pyrrolidine-2,5-diones (N-amino-succin­imides) through the multicomponent reaction of aldimines, Meldrum’s acid and N-isocyanimino-triphenylphosphorane. The imine must be preformed, as attempted use of p-chlorobenzaldehyde and aniline separately did not give useful yields of the succinimide. The starting phosphorane is commercially available and is somewhat expensive, but it can be easily synthesized from inexpensive formic hydrazide and triphenylphosphine in the presence of DBU and CCl₄ (M. M. Bio et al. Synthesis 2005, 19). A mechanism for the reaction is proposed (shown above) and is consistent with the known reactivity of the reagents. Although the requirement for water is demonstrated, the quantity required is not specified. Pre-sumably the water absorbed by THF from the ­atmosphere is sufficient.