Synthesis of novel 4H-1,2,4-triazole-3-thiol derivatives with 2-(2,6-dichlorophenylamino)benzyl fragment in molecules and their anti-inflammatory activity

Abstract

Aim. The study of anti-inflammatory activity of novel 4H-1,2,4-triazole-3-thiol derivatives is one of the most priority direction of pharmacological investigation of mentioned heterocyclic system. Methods and results. Based on the heterocyclization reaction of N-substituted thiosemicarbazides in alkaline medium the synthesis of novel non-condensed derivatives with 4H-1,2,4-triazole and 2-(2,6-dichlorophenylamino)benzyl fragments was carried out. Further chemical modification of synthesized 5-[2-(2,6-dichlorophenylamino)benzyl]-4H-1,2,4-triazole-3-thioles was performed via S-alkylation reactions with N-aryl(thiophene-2-yl)substituted 2-chloroacetamides and 2-chloro-1-(3,5-diaryl-4,5-dihydropyrazol-1-yl)ethanones. Structure of synthesized compounds was confirmed by the elemental analysis and 1H NMR spectral data. Conclusions. The research of anti-inflammatory activity has been conducted on the carrageenan-induced edema of the rat’s extremities model. The results allow to identify highly active compounds 2-{5-[2-(2,6-dichloro-phenylamino)-benzyl]-4-ethyl-4Н-[1,2,4]triazol-3-ylsulfanyl}-N-(4-chlorophenyl)acetamide (compound 3b) and 2-{5-[2-(2,6-dichloro-phenylamino)-benzyl]-4-ethyl-4Н-[1,2,4]triazol-3-ylsulfanyl}-1-[5-(4-methoxy-phenyl)-3-(naphthalen-2-yl)-4,5-dihydro-pyrazol-1-yl]-ethanone (compound 5c) with evident antiexudative effect comparable with the same effect of diclofenac sodium.

Keywords

• 4H-1 2 4-triazole
• Diclofenac
• Alkylation
• Anti-Inflammatory Agents