Synthesis 2019; 51(22): 4205-4214
DOI: 10.1055/s-0039-1690616
paper
© Georg Thieme Verlag Stuttgart · New York

Acid-Catalyzed Condensation of o-Phenylenediammines and o-Aminophenols with α-Oxodithioesters: A Divergent and Regio­selective Synthesis of 2-Methylthio-3-aryl/Heteroarylquinoxalines and 2-Acylbenzoxazoles

Kuppalli R Kiran
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
,
b   Department of Studies in Organic Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: swarooptr@gmail.com
,
Kodipura P Sukrutha
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
,
Jeegundipattana B Shruthi
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
,
Seegehally M Anil
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
,
Kanchugarakoppal S Rangappa
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
,
a   Department of Studies in Chemistry, University of Mysore, Manasagangothri, Mysuru, 570 006, India   Email: rangappaks@gmail.com   Email: mpsadashiva@gmail.com
› Author Affiliations
Authors are grateful to the University Grants Commission-Special Assistance Programme, Departmental Research Support (UGC-SAP DRS III) for providing financial support.
Further Information

Publication History

Received: 26 June 2019

Accepted after revision: 06 August 2019

Publication Date:
23 September 2019 (online)


Abstract

o-Phenylenediammines and o-aminophenols were reacted with α-oxodithioesters in a highly regioselective fashion to give 2-methylthio-3-aryl/heteroarylquinoxalines and 2-acylbenzoxazoles in 55–94% and 45–86%, respectively, in the presence of p-toluene sulfonic acid catalyst. Control experiments involving reaction of aniline with a α-oxodithioester indicated that the thiocarbonyl group is more reactive than the carbonyl group. Based on this, probable mechanisms for the formation of quinoxalines and benzoxazoles are given. Biological targets of the quinoxalines and benzoxazoles were identified by bioinformatics. It was found that quinoxalines have good binding affinity with human dual-specificity tyrosine-phosphorylation-regulated kinase 1A and benzoxazoles with human carboxylesterase.

Supporting Information