1,2,4-Oxadiazoles: Synthesis and Applications

Abstract

1,2,4-Oxadiazole are compounds that have attracted the attention of many researchers due to their wide range of biological activities. Methods used for the synthesis of 3,5-substituted 1,2,4-oxadiazoles are reviewed in this works, as well as their applications. The syntheses are based mostly on the use of primary amidoximes and acylating agents as the initial reactants. In the last years, numerous reports concerning new methods of synthesis of 1,2,4-oxadiazoles have been reported. The use of microwave irradiation and ultrasound in chemical synthesis has many advantages with consequent impacts on the economy and the environment.

Synthesis and Antibacterial Evaluation of 3,5-Diaryl-1,2,4-oxadiazole Derivatives

“…Chemical shifts (d) are reported in ppm relative to tetramethylsilane. The solvent used was CDCl 3 and dimethylsulfoxide-d 6 (DMSO-d 6 ) and the coupling constant (J) is given in hertz (Hz). Multiplicities were presented as singlet (s), doublet (d), triplet (t), quadruplet (q) and multiplet (m).…”

“…4 Although the 1,2,4-oxadiazole heterocycle was first synthesized in 1884, 5 it was only in the 1990s that this nucleus aroused interest within the scientific community. 6 The literature reports a diverse set of applications for the 1,2,4-oxadiazole core in medicinal chemistry, 7,8 such as antiasthmatic, 9 antidiabetic, 10 antitumoral, 11 anti-inflammatory, 12 antioxidant, 12 and antimicrobial. 13 Different parameters are used to quantify these biological activities, such as half maximal inhibitory concentration (IC 50 ), half maximal effective concentration (EC 50 ) or minimum inhibition concentration (MIC) (Figure 2).…”