Mannich Reaction of α-Aminomaleimides with Imines

A novel Mannich reaction of α-aminomaleimides with N-arylsulfonylimines was conducted in dimethyl sulfoxide using molecular sieves 4A. Remarkably promising new maleimide derivatives were efficiently and readily synthesized under mild reaction conditions. The Mannich reaction of α-aminomaleimides with N-arylsulfonylimines in the presence of MS 4A in DMSO was conducted. The reaction proceeds smoothly under mild reaction conditions. Moreover, a wide range of substrates are well tolerated to provide various Mannich products—new valuable maleimide derivatives bearing multiple nitrogen atoms—in high to excellent yields.