Synthesis 2019; 51(19): 3600-3610
DOI: 10.1055/s-0037-1611854
paper
© Georg Thieme Verlag Stuttgart · New York

PhI(OAc)2-Mediated Regioselective Synthesis of 5-Guanidino-1,2,4-thiadiazoles and 1,2,4-Triazolo[1,5-a]pyridines via Oxidative N–S and N–N Bond Formation

Tumula Nagaraju
a   Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India   Email: mangarao@csiriict.in
b   Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India
,
a   Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India   Email: mangarao@csiriict.in
,
Balasubramanian Sridhar
c   Center for X-ray Crystallography, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
,
Nakka Mangarao
a   Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India   Email: mangarao@csiriict.in
› Author Affiliations
The authors thank the SERB, New Delhi, India for financial support in the form of NPDF (PDF/2016/000177).
Further Information

Publication History

Received: 15 February 2019

Accepted after revision: 24 April 2019

Publication Date:
08 July 2019 (online)


Abstract

An effective and expeditious approach for the construction of biologically important 5-guanidino-1,2,4-thiadiazole and 1,2,4-triazolo[1,5-a]pyridine derivatives has been developed. This new protocol involves the phenyliodine(III) diacetate [PhI(OAc)2]-mediated oxidative cyclization of thioureas/2-aminopyridines and imidates via N–S and N–N bond formation at ambient temperature. This method furnishes the versatile 5-guanidino-1,2,4-thiadiazoles and 1,2,4-triazolo[1,5-a]pyridines in a scalable manner with high efficiency and excellent regioselectivity.

Supporting Information