Synthesis of 2,4-Disubstituted Quinolines in Deep Eutectic Solvents

In the deep eutectic solvent which composed of choline chloride and zinc chloride, a series of 2,4-disubstituted quinolines were synthesized via cyclization coupling of 2-aminoacetophenone and aromatic alkyne. When the molar ratio of choline chloride and zinc chloride was 1:2, the yield up to 98% was achieved at 80 degrees C for 3 h. The method does not need additional catalyst, and has the advantages of mild reaction conditions, simple operation and a wide range of substrates.