Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues

Rashmi Singh; Tomas Horsten; Rashmi Prakash; Swapan Dey; Wim Dehaen

doi:10.3762/bjoc.17.79

Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues

Beilstein J Org Chem. 2021 Apr 30:17:977-982. doi: 10.3762/bjoc.17.79. eCollection 2021.

Authors

Rashmi Singh^{1

2}, Tomas Horsten², Rashmi Prakash², Swapan Dey¹, Wim Dehaen²

Affiliations

¹ Department of Chemistry, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad 826004, India.
² Department of Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.

Abstract

Several new heterocyclic systems based on a hydroxybenzofuro[2,3-b]pyridine building block were prepared. This benzofuropyridine is easily available from the Meerwein reaction of benzoquinone and a heterocyclic diazonium salt, followed by reduction and cyclization. Electrophilic substitution and further condensations give polycyclic systems, including oxazolo- and chromeno-fused analogues.

Keywords: Meerwein reaction; benzofuropyridines; benzoquinones; dibenzofurans; metal-free synthesis.

Grants and funding

We thank the KU Leuven for financial support. KU Leuven (Project C14/19/78). R. S. thanks IIT (ISM) Dhanbad for a graduate fellowship. Mass spectrometry was made possible by the support of the Hercules Foundation of the Flemish Government (grant 20100225-7).