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

The 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.

Progress in the Synthesis of Fused 1,2,3‐Triazoles

“…Elimination of routine workup and extraction is its greener vision. Fülöpová et al [88] . disclosed a high yielding solid phase synthesis of benzo[ f ][1,2,3]triazolo[1,5‐ a ][1,4]diazepin‐6(5H)‐ones and 4,5‐dihydrobenzo[ f ][1,2,3]triazolo[1,5‐ d ][1,2,5]thiadiazepine 6,6‐dioxide derivatives 276 under mild and catalyst free conditions.…”

Solid-Phase Synthesis of Seven-Membered Heterocycles with Two Nitrogen Atoms

“…Furthermore, employing 2-Nos-Cls and benzothiadiazepine 1,1-dioxides was recently obtained from polymer-supported α-amino acids using alcohols as the building blocks for the Fukuyma-Mitsunobu N 2 -alkylation [62]. The previously mentioned method was further modified to prepare triazolobenzodiazepinones and triazolobenzothiadiazepine 1,1-dioxides [63]. Starting from the intermediates 158, the alkylation with propargyl bromides was performed.…”

Copper‐Free Solid‐Phase Synthesis of Triazolo[1,5‐a][1,4]diazepin‐6‐ones

“…Compared to the CuAAC, non‐catalysed Huisgen cycloaddition on resin was reported much less frequently. Recently, we developed a solid‐phase synthesis method for triazolobenzodiazepinones based on the spontaneous AAC of immobilized propargyl‐azidobenzamides [9] . The preparation of triazolobenzodiazepinones was also reported by others using different approaches [10–15] .…”