Cyanoquinolines and Furo[3,4- b]quinolinones Formation via On-The-Spot 2,3-Functionalization of Quinolines with Cyanopropargylic Alcohols

Kseniya V Belyaeva; Lina P Nikitina; Andrey V Afonin; Ludmila A Grishchenko; Boris A Trofimov

doi:10.1021/acs.joc.0c02644

Cyanoquinolines and Furo[3,4- b]quinolinones Formation via On-The-Spot 2,3-Functionalization of Quinolines with Cyanopropargylic Alcohols

J Org Chem. 2021 Mar 5;86(5):3800-3809. doi: 10.1021/acs.joc.0c02644. Epub 2021 Feb 19.

Authors

Kseniya V Belyaeva¹, Lina P Nikitina¹, Andrey V Afonin¹, Ludmila A Grishchenko¹, Boris A Trofimov¹

Affiliation

¹ A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 1 Favorsky Str., Irkutsk 664033, Russian Federation.

PMID: 33605731
DOI: 10.1021/acs.joc.0c02644

Abstract

A convenient approach to 2-(1-ethoxyalkoxy)-3-cyanoquinolines (in up to 50% yields) has been developed. The approach comprises functionalization of quinolines with acetals of cyanopropargylic alcohols (KOH/H₂O/MeCN, 55-60 °C) followed by their transformation to furo[3,4-b]quinolinones (in up to 98% yields) via the sequential removal of acetal protection and intramolecular cyclization/hydration (7% aqueous HCl, acetone, 20-25 °C).