Synthesis 2024; 56(20): 3173-3180
DOI: 10.1055/s-0043-1775390
paper

1,3-Dipolar Cycloaddition Reaction of Nitrile Oxide to Thiocyanates: An Efficient and Eco-Friendly Synthesis of N-Aryl-2-((3-aryl-1,2,4-oxadiazol-5-yl)thio)acetamides

Vamshikrishna Y. Radhakrishna
a   Department of Chemistry, REVA University, Yelahanka, Bangalore, Karnataka 560064, India
,
Gopal L. Khatik
b   Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Raebareli 226002, Uttar Pradesh, India
,
Vipin A. Nair
c   School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri Campus, Clappana, Kollam, Kerala 690525, India
› Author Affiliations
Vipin A. Nair acknowledges with gratitude the funding received in the form of a research grant (Grant No. 02/0447/21/EMR-II) from the Human Resource Development Group, Council of Scientific and Industrial Research, Government of India.


In memory of an organic chemist, the late Dr. G. Vijay Nair

Abstract

An efficient and eco-friendly procedure was developed for the synthesis of N-aryl-2-((3-aryl-1,2,4-oxadiazol-5-yl)thio)acetamides from N-aryl-2-thiocyanatoacetamides and substituted N-hydroxybenzimidoyl chlorides that were prepared easily from the commercially available anilines and aryl aldehydes, respectively. The N-aryl-2-thiocyanatoacetamide acts as a dipolarophile while the nitrile oxide formed in situ from substituted N-hydroxybenzimidoyl chloride acts as the nucleophilic partner in a 1,3-dipolar cycloaddition reaction mediated by triethylamine base in ethanol medium. The procedure affords excellent yields of desired products containing electron-withdrawing and electron-donating groups on the aromatic rings, in short reaction time with ease of operation. The procedure for the synthesis of scaffolds that are potentially valuable for their biological properties also offers the possibility of scale-up to higher quantities.

Supporting Information



Publication History

Received: 13 June 2024

Accepted after revision: 16 July 2024

Article published online:
06 August 2024

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