Enol ethers as carbonyl surrogates in a modification of the Povarov synthesis of 3-aryl quinolines and their anti-Toxoplasma activity†
Carla E. Brown,James McNulty,Claudia Bordón,Robert Yolken,Lorraine Jones-Brando
Organic & Biomolecular Chemistry Pub Date : 05/26/2016 00:00:00 , DOI:10.1039/C6OB01083K
Abstract

A novel method for the preparation of 2-carboxyl-3-aryl quinoline derivatives from anilines, ethyl glyoxalate and enol ethers as phenylacetaldehyde surrogates is reported. The three-component coupling reaction occurs rapidly under mild conditions in dichloromethane catalysed by TFA. The method allows a more direct access to 3-aryl quinolines, sidestepping issues encountered with phenylacetaldehyde derivatives. This chemistry was used to prepare quinolines with 3-diarylether functionality that showed low micromolar efficacy (IC50 range: 5–26 μM) against in vitro Toxoplasma gondii coupled with little or no cytotoxicity (TD50 ≥ 320 μM) towards the host cells.

Graphical abstract: Enol ethers as carbonyl surrogates in a modification of the Povarov synthesis of 3-aryl quinolines and their anti-Toxoplasma activity