Publication Cover
Synthetic Communications
An International Journal for Rapid Communication of Synthetic Organic Chemistry
Volume 54, 2024 - Issue 1
278
Views
0
CrossRef citations to date
0
Altmetric
Articles

Base promoted coupling of α-ketoacids and 2-substituted aromatic amines: Green synthesis of diverse benzoxazoles, benzothiazoles, quinoxalinones and benzoxazinones and its practical application

, &
Pages 50-65 | Received 01 Aug 2023, Published online: 15 Nov 2023
 

Abstract

Synthesis of 2-aryl substituted benzoxazoles, benzothiazoles, and quinoxalinones via decarboxylative coupling of α-keto acids with 2-aminophenol, 2-aminothiophenol, and OPD (o-phenylenediamine), using K2CO3 as a base in water at room temperature, and as well as solvent-free grinding and the synthesis of benzoxazinones from the reaction of α-keto acids with 2-aminophenol at 60 °C have been reported. Both the protocols afforded a wide range of desired products with excellent functional group tolerance in yields of 87–99%. The major advantages of these approaches are catalyst-free protocol, short reaction times, straightforward workup, and chromatography-free processing of the products. Additionally, to test the translational demand of this methodology, the synthesis of 2-(3,5-dichlorophenyl)-6-methylbenzo[d]oxazole was carried out which is a key structure of tafamidis, a commercially available drug.

Graphical Abstract

Acknowledgments

R.B.R.D.Y. is grateful to DST-SERB, New Delhi, for the Early Career Research Award [Grant No. ECR/2016/001041] and S. M. is thankful to DST-SERB for the fellowship. We also thank the SASTRA Deemed University for providing lab space.

Additional information

Funding

The authors gratefully acknowledge the DST-FIST NMR facility [Grant No. SR/FST/CS-I/2018/62] at the Department of Chemistry, SASTRA Deemed University. This work was supported by Science and Engineering Research Board.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.