Ring-fused derivatives 1.2.4- triazoles

Synthesis of Triazoles and Ring-Fused Derivatives via Nitrogenation Strategy... 

Mercapto-4-amino[l,2,4]triazole can also be transformed to derivatives of the title ring system by 1,3-dioxo reagents. These transformations are summarized in Table 6. In most of these cases, 5,5-dimethylcyclohexane-l,3-dione was used, and, accordingly, this procedure can lead to some cyclohexenyl-fused derivatives. 

Some related cyclic scaffolds, such as the azepines, were obtained by Ugi-4CR/ RCM combinations (Fig. 5a) [61], and fused benzodiazepine/triazole frameworks were derived from sequential Ugi-4CR/alkyne-azide dipolar cycloaddition (Fig. 5b) [62]. Both are considered as interesting (3-tum mimics. Similarly, bicyclic systems featuring fused DKP rings (Fig. 5c) have been reported to mimic the ten-membered pseudo-cycle of type 1 (3-tums [63, 64]. 

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