3-Benzoylamino-1,2,4-triazoles from N-Dichloromethylene-benzamide and Amidrazones

Synthesis of 1,2,4-triazolo[4,3-a][1,8]Naphthyridines using Chloranil under Microwave Irradiation

“…In conclusion, we have demonstrated a convenient and highly efficient protocol for the synthesis of 1,2,4-triazolo[4,3-a] [1,8]naphthyridines using chloranil under microwave irradiation. The significant advantages of the procedure are operational simplicity, short reaction time, pure products and high yields.…”

“…as energy transfer media which absorb microwave energy efficiently through dipole rotation. In view of this and in continuation of our interest in microwave-assisted organic transformations on 1,8-naphthyridine derivatives, [18][19][20][21] we report here, a convenient, practical and efficient method for the synthesis of 1,2,4-triazolo [4,3-a] [1,8]naphthyridines using chloranil under microwave irradiation.…”

“…Oxidative cyclisation of 7 with chloranil in 1,2-dichloroethane under microwave irradiation furnished the respective 1-aryl-4-(p-bromophenyl)-1,2,4-triazolo [4,3-a] [1,8] naphthyridines (8) (Scheme 1). The oxidative transformation is clean and efficient.…”

“…The precipitate thus obtained was filtered, washed with water and recrystallised from ethanol to give 7. General procedure for the synthesis of 1-aryl-4-(p-bromophenyl)-1,2,4-triazolo [4,3-a] [1,8]naphthyridines (8): To a solution of 7 (0.01 mol) in 1,2-dichloroethane (20 ml), chloranil (0.01 mol) was added. The reaction mixture was subjected to microwave irradiation at 200 watts intermittently at 30 s intervals for the specified time (Table 1).…”

Solid-Phase Synthesis of 3-Alkylamino-1,2,4-triazoles

“…Numerous methods have been developed for the solution-phase synthesis of 3-amino-1,2,4-triazoles. These include the reaction of aminoguanidines with carboxylic acids and cyclization of hydrazones made from aminoguanidines or amidrazones with carbodiimides . Moreover, 3-alkylamino analogues have been prepared from preformed 3-aminotriazoles by reductive alkylation…”