A three-step synthesis of imidazole core from arylethanolamines was achieved. A key to this sequence is a Ritter reaction of arylethanolamines promoted by perchloric acid, allowing the formation of 2-methylamino-1-(acylamino)-1-arylethanes in 33–82% yields. The latter were subjected to thermal cyclization into 4-arylimidazolines by simple heating in n-butanol in 51–95% yields or to one-pot cyclization-oxidation sequence to produce 2,4-diarylimidazoles in 73–93% yields. The efficiency of this approach was demonstrated on a straightforward one-pot synthesis of 2,4-diarylimidazoles from readily available starting materials: aromatic aldehydes, sarcosine, paraformaldehyde and benzonitriles, in 42–49% total yields. © 2023 Wiley-VCH GmbH.