Protocol for the synthesis of N-Alkyl bromomaleimide linkers

Herein a straightforward and efficient method for synthesizing bromomaleimides with varied carbon chain lengths to modulate molecular properties has been reported. Compounds <b>1-4</b> incorporate a single bromomaleimide unit, while compound <b>5</b> features two, enabling dual functionalization. This synthetic approach consistently yields high-purity products in good to excellent yields, with compound <b>5</b> offering potential for dual payload conjugation due to its bifunctional structure. The key highlights are: 1. Bromomaleimides offers exceptional stability compared to maleimides counterparts 2. Highly selective for Cysteine modification.