The creation of procedures for the environmentally friendly synthesis of materials and chemicals is
referred to as "green synthetic protocol." The synthesis of different biologically active compounds is
done through energy-efficient and environmentally safe processes like microwave irradiation
technology, ultrasound-mediated synthesis, photo-catalysis (ultraviolet, visible, and infrared
irradiation), molecular sieving, grinding, and milling techniques, etc. These procedures are regarded
as sustainable technology and have gained value as green protocols for the synthesis of novel
medicinal compounds because they have several advantages over traditional synthetic techniques.On
the basis of this idea, Oxadiazole derivatives are made using a microwave irradiation approach to
decrease the amount of byproduct generated and boost the product yield quantitatively in a shorter
amount of reaction time. Because of this, the synthesis of pharmacological molecules under microwave
irradiation adheres to a green chemistry strategy, which uses a set of guidelines to reduce or eliminate
the use of dangerous and toxic ingredients in the design, production, and use of chemicals. By using
cleaner solvents, catalysts, and appropriate reaction conditions, this strategy helps to reduce
environmental pollution and boosts energy efficiency and atom economy. Oxadiazole is a heterocyclic
molecule with five members that has two nitrogen and one oxygen atoms in its ring system. The
oxadiazole moiety is garnering a lot of interest in the development of novel drug candidates due to its
potential therapeutic activities, which include antibacterial, antifungal, antiviral, anticonvulsant,
anticancer, antimalarial, antitubercular, anti-asthmatic, antidepressant, anti-diabetic, antioxidant,
antiparkinsonian, analgesic, and anti-inflammatory properties. This review focuses on the many
synthesis methods for oxadiazole derivatives that are heated using a microwave and the investigation
of their diverse biological functions.

1. Verma, S.K.; Verma, R.; Verma, S.; Vaishnav, Y.; Tiwari, S.; Rakesh, K. Anti-tuberculosis activity and its structure-activity relationship (SAR) studies of oxadiazole derivatives: A key review. Eur. J. Med. Chem. 2021, 209, 112886. 2. Baral, N.; Mohapatra, S.; Raiguru, B.P.; Mishra, N.P.; Panda, P.; Nayak, S.; Pandey, S.K.; Kumar, P.S.; Sahoo, C.R. Microwave-Assisted Rapid and Efficient Synthesis of New Series of Chromene Based 1,2,4-Oxadiazole Derivatives and Evaluation of Antibacterial Activity with Molecular Docking Investigation. J. Heterocycl. Chem. 2019, 56, 552–565. 3. Reddy, M.L.C.; Khan, F.N.; Saravanan, V. Facile synthesis of N-1,2,4-oxadiazole substituted sulfoximines from N-cyano sulfoximines. Org. Biomol. Chem. 2019, 17, 9187–9199. 4. Sahoo, B.M.; Ravi Kumar, B.V.V.; Banik, B.K.; Borah, P. Green Efficient Synthesis of Oxadiazole Derivatives as Analgesic and Anti-inflammatory Agents. Curr. Green Chem. 2020, 7, 163–178. 5. Tawfik, S.S.; Liu, M.; Farahat, A.A. Antiviral activity of thiadiazoles, oxadiazoles, triazoles and thiazoles. Arkivoc 2020, 180–218. 6. Biernacki, K.; Daśko, M.; Ciupak, O.; Kubiński, K.; Rachon, J.; Demkowicz, S. Novel 1,2,4 Oxadiazole Derivatives in Drug Discovery. Pharmaceuticals 2020, 13, 111. 7. Benassi, A.; Doria, F.; Pirota, V. Groundbreaking Anticancer Activity of Highly Diversified Oxadiazole Scaffolds. Int. J. Mol. Sci. 2020, 21, 8692. 8. Verma, G.; Khan, M.F.; Akhtar, W.; Alam, M.M.; Akhter, M.; Shaquiquzzaman, M. A Review Exploring Therapeutic Worth of 1,3,4-Oxadiazole Tailored Compounds. Mini-Rev. Med. Chem. 2019, 19, 477–509. 9. Valentina, N.M.; Franciane, G.; Ferreira, V.P.G.; Araujo, H.M.; do Ó Pessoa, C.; Nicolete, R.; de Oliveira, R.N. Focused microwave irra-diationassisted synthesis of N-cyclohexyl-1,2,4 oxadiazole derivatives with antitumor activity. Synth. Commun. 2018, 48, 2522–2532. 10. Guerrero, M.; Urbano, M.; Kim, E.K.; Gamo, A.M.; Riley, S.; Abgaryan, L.; Leaf, N.; Van Orden, L.J.; Brown, S.J.; Xie, J.Y.; et al. Design and Synthesis of a Novel and Selective Kappa Opioid Receptor (KOR) Antagonist (BTRX-335140). J. Med. Chem. 2019, 62, 1761–1780. 11. Dai, X.; Yan, X.; Wintergerst, K.A.; Cai, L.; Keller, B.B.; Tan, Y. Nrf2: Redox and Metabolic Regulator of Stem Cell State and Function. Trends Mol. Med. 2020, 26, 185–200. 12. Kozak, W.; Demkowicz, S.; Daśko, M.; Rachon, J.; Rak, J. Modifications at the C(5) position of pyrimidine nucleosides. Russ. Chem. Rev. 2020, 89, 281–310. 13. Xu, L.L.; Wu, Y.F.; Yan, F.; Li, C.C.; Dai, Z.; You, Q.D.; Jiang, Z.Y.; Di, B. 5-(3,4 Difluorophenyl)-3-(6-methylpyridin-3-yl)-1,2,4-oxadiazole (DDO-7263), a novel Nrf2 activator targeting brain tissue, protects against MPTP-induced subacute Parkinson’s disease in mice by inhibiting the NLRP3 inflammasome and protects PC12 cells aga. Free Radic. Biol. Med. 2019, 134, 288–303. 14. Coleman, K.G.; Crews, C.M. Proteolysis-Targeting Chimeras: Harnessing the Ubiquitin Proteasome System to Induce Degradation of Specific Target Proteins. Annu. Rev. Cancer Biol. Online 2018, 2, 41–58. 15. Clark, S.D.; Abi-Dargham, A. The Role of Dynorphin and the Kappa Opioid Receptor in the Symptomatology of Schizophrenia: A Review of the Evidence. Biol. Psychiatry 2019, 86, 502 511. 16. Tejeda, H.A.; Bonci, A. Dynorphin/Kappa-opioid receptor control of dopamine dynamics: Implications for negative affective states and psychiatric disorders. Brain Res. 2019, 1713, 91 101. 17. Ge, L.; Guyatt, G.; Tian, J.; Pan, B.; Chang, Y.; Chen, Y.; Li, H.; Zhang, J.; Li, Y.; Ling, J.; et al. Insomnia and risk of mortality from all-cause, cardiovascular disease, and cancer: Systematic review and meta-analysis of prospective cohort studies. Sleep Med. Rev. 2019, 48, 101215. 18. Bhandari, M.; Raj, S. Practical Approach to Green Chemistry. Int. J. Pharm. Pharm. Sci. 2017, 9, 10–26. 19. Bala, S.; Kamboj, S.; Kumar, A. Heterocyclic 1,3,4-oxadiazole compounds with diverse biological activities: A comprehensive review. J. Pharm. Res. 2010, 3, 2993–2997. 20. Baykov, S.; Sharonova, T.; Shetnev, A.; Rozhkov, S.; Kalinin, S.; Smirnov, A.V. The first one pot ambient-temperature synthesis of 1,2,4-oxadiazoles from amidoximes and carboxylic acid esters. Tetrahedron 2017, 73, 945–951. 21. McDonald, C.M.; Campbell, C.; Torricelli, R.E.; Finkel, R.S.; Flanigan, K.M.; Goemans, N.; Heydemann, P.; Kamińska, A.M.; Kirschner, J.; Muntoni, F.; et al. Ataluren in patients with nonsense mutation Duchenne muscular dystrophy (ACT DMD): A multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet 2017, 390, 1489–1498.