Solid‐Phase Synthesis of Trisubstituted Benzo[f][1,2,3]triazolo[1,5‐a][1,4]diazepin‐6(5H)‐ones and Their Sulfonyl Analogues under Mild Reaction Conditions

Abstract

AbstractThe solid‐phase synthesis of 4H‐benzo[f][1,2,3]triazolo[1,5‐a][1,4]diazepin‐6(5H)‐ones and 4,5‐dihydrobenzo[f][1,2,3]triazolo[5,1‐d][1,2,5]thiadiazepine 6,6‐dioxides under mild and catalyst‐free conditions is described. The seven‐step synthetic strategy is based on the preparation of polymer‐supported 4‐nitrobenzenesulfonamides and their alkylation with various propargyl derivatives. Cleavage of the 4‐nitrobenzenesulfonyl group from each of the key intermediates was followed by acylation with different 2‐azidobenzoic acids, leading to spontaneous intramolecular (Huisgen) 1,3‐dipolar cycloaddition. After cleavage from the polymer support, the target compounds were obtained in excellent crude purities and very good overall yields.