Title:A Facile and Efficient One-pot Three Component Route to New Bis(1,2,4- Oxadiazole) Linked with Polyoxyethylene Chain
Volume: 14
Issue: 4
Author(s): Saad Ghrab*, Lotfi Aroua and Mohamed Beji
Affiliation:
- Laboratory of Organic Structural Chemistry & Macromolecules, Department of Chemistry, Faculty of Sciences, Tunis-El Manar University, 2092 Tunis,Tunisia
Keywords:
Oligoethylene diglycidyl ether, hydroxynitrile, PEG, 1, 2, 4-oxadiazole, amidoxime, heterocycles, green chemistry.
Abstract: Background: The synthesis of effective drugs is very important for the scientist. Due to the
beneficial pharmacological properties of certain molecules containing the 1,2,4-oxadiazole moiety, the
aim of this manuscript is to develop a one pot three component reaction for the synthesis of bis (3, 5-
disubstituted 1,2,4-oxadiazoles) bridged by polyoxyethylene chain from bis(β-hydroxynitrile) of polyethylene
glycols under neutral and organic solvent-free reaction conditions. These compounds have
gained too much interest as proven by large number of reviews and research articles published in the
current years. The synthesis of a series of bis (3, 5-disubstituted 1,2,4-oxadiazoles) has initially been
stimulated by their known antimalaria properties.
Methods: A one-pot two-step synthesis of a new bis (3, 5-disubstituted 1,2,4-oxadiazoles) linked with
polyoxyethylene chain was realized starting from the reaction of aqueous hydroxylamine with bis (β-
hydroxynitrile) polyoxyethylene obtained in turn by ring opening of oligoethylene diglycidyl ethers
under mild conditions. The identity and purity of the products were confirmed by IR, 1H NMR, 13C
NMR and HRMS.
Results: The synthesized compounds with different chain lengths were obtained in satisfactory to good
yields (41-74%).This methodology presented the advantage of being relatively eco-friendly, short reaction
times, versatile and avoid the use of organic solvent.
Conclusion: This work presents simple direct route to the important structure containing two oxadiazole
groups bridged by a polyoxyethylene chain 3(a-d), which would facilitate relevant studies on the
pharmacological properties of these oxadiazole derivatives.
