Synthesis 2024; 56(09): 1465-1475
DOI: 10.1055/s-0042-1751555
paper

Tertiary Amines as Temporary Masked Secondary Amines: A Direct Access to 5-Dialkylamino-1,2,4-oxadiazoles from 1,2,4-Oxadiazol-5(4H)-ones

Authors

  • Muh Alfliadhi

    a   Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
  • Mookda Pattarawarapan

    a   Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
  • Surat Hongsibsong

    b   Environmental, Occupational Health Sciences and Non Communicable Diseases Center of Excellence, Chiang Mai University, Chiang Mai 50200, Thailand
    c   School of Health Science Research, Research Institute for Health Science, Chiang Mai University, Chiang Mai 50200, Thailand
  • Nittaya Wiriya

    a   Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
  • Wong Phakhodee

    a   Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand

Financial support for this work was partially provided by Chiang Mai University (Grant No. MRCMU2566R_016 to W.P.).


Graphical Abstract

Preview

Abstract

A novel strategy utilizing tertiary amines as temporary masked secondary amines to synthesize 5-dialkylamino 1,2,4-oxadiazoles via Ph3P-I2 mediated amination of 1,2,4-oxadiazol-5(4H)-ones was developed. A one-step N-dealkylative functionalization of tertiary amines with the 1,2,4-oxadiazole ring enables a convenient access to diverse 5-amino-1,2,4-oxadiazoles. Additionally, orthogonally functionalized piperazine derivatives can be effectively constructed through site-selective reaction of 1,4-dialkylpiperazines or via a sequential N-functionalization of 1-methylpiperazine obviating laborious protection/deprotection steps.

Supporting Information



Publication History

Received: 06 December 2023

Accepted after revision: 17 January 2024

Article published online:
12 February 2024

© 2024. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany