Synthesis 2020; 52(13): 1981-1990
DOI: 10.1055/s-0039-1690855
paper
© Georg Thieme Verlag Stuttgart · New York

Potassium Periodate Mediated Oxidative Cyclodesulfurization toward Benzofused Nitrogen Heterocycles

Chuthamat Duangkamol
a   Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
,
Wong Phakhodee
a   Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
b   Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand   Email: Mookdap55@gmail.com
,
Mookda Pattarawarapan
a   Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
b   Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand   Email: Mookdap55@gmail.com
› Author Affiliations
This work was supported by The Thailand Research Fund through the Royal Golden Jubilee Ph.D. Programme (Grant No. PHD/0086/2557) to C.D. This research work was also partially supported by Chiang Mai University and the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Office of the Higher Education Commission, Ministry of Education, Thailand.
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Publication History

Received: 02 January 2020

Accepted after revision: 26 February 2020

Publication Date:
16 March 2020 (online)


Abstract

A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho-substituted anilines bearing N,N-, N,O-, and N,S-bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free.

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