Comprehensive approach to the multigram, heavy-metal-free synthesis of 4-EWG-substituted quinoline derivatives

2-Nitrotoluenes activated by CN, SO2Tol, CO2R or COR groups condense under particular conditions with acetaldehyde in moderate to excellent yields. The unsaturated products are starting materials for cyclization furnishing quinoline oxides substituted with the above electron-withdrawing groups. Under relevant reaction conditions they can be reduced to the corresponding substituted quinolines. The protocol is suitable for multigram scale and extends the scope of the condensation step on non–CN–substituted 2-nitroarenes. [Display omitted]