Synthesis And Characterization Of Some Bis.1,2,3,4-Tetrazoline Derivatives And Their Antioxidant Activity

Abstract

In this study, we describe the synthesis of 1,2,3 and 4 tetrazoline derivatives from D-Mannitol. The initial step of the synthetic route involved obtaining azido D-Mannitol (ATN₃) as an intermediate by treating 1,2:5,6-Di-O-isopropylidene-3,4-di-p-tosyl-D-Mannitol AT with sodium azide. The intermediate (ATN₃) was subsequently reacted with Schiff base derivatives (BS₁; BS₂), leading to formation of 1,2,3 and 4-tetrazoline. The last two deprotected products (DS₁ and DS₂) were synthesized through the hydrolysis of acetal groups with dilute solution 15% AcOH. The synthesized compounds were characterized by FT-IR, ¹₁H-NMR and¹³C-NMR spectroscopy alongside Thin Layer Chromatography (TLC). The DPPH radical scavenging assay was used to assess antioxidant potential. Results indicated that derivatives DS and HS₁ are extremely potent antioxidants"Very Active," classifying them with IC₅₀ of 0.42, and 4.31 µg/mL respectively, DS₁ presented a potency more than 10-fold superior to the ascorbic acid standard with fast and stable kinetics in the first 5 minutes. The results indicate that these derivatives of tetrazoline are potentially useful for further pharmacology investigations.