Metal Free Sulfonic Acid Functionalized Carbon Catalyst for Green and Mechanochemical Synthesis of Perimidines

A new and scalable mechanochemical approach has been developed for the synthesis of perimidine derivatives using an efficient and recyclable catalyst, carbon sulfonic acid under metal-free conditions. A wide variety of aldehydes displayed cyclo-condensation reaction with 1,8-diaminonaphthalene in EtOH under ambient reaction conditions via grind-stone technique to produce substituted perimidines in excellent yields (95-99 %) in a very short reaction time. This method has interesting features like single-step synthesis, high functional group tolerance, transition-metal free synthesis, high atom-economy, recyclable catalyst, no need of tedious purification process, gram-scale synthesis, high green chemistry matrix (Eco-score and E-factor) that make this protocol green and eco-friendly.