An efficient reverse Diels–Alder approach for the synthesis of N-alkyl bismaleimides

Bismaleimides are useful precursors for Diels–Alder reactions, Michael additions, and thiol–maleimide based conjugation for the synthesis of materials and polymers. Use of bismaleimide cross linkers for generating polymers, bioconjugate molecules, and useful imaging molecules is an active area of research. An efficient and practical synthetic protocol for N-alkyl bis-maleimide cross linkers starting from furan protected maleimide employing a reverse Diels–Alder reaction is reported.