Constructing 5‐Methyl‐2,4‐diaryl‐1H‐imidazoles Using Calcium Carbide as Alkyne Source via A3‐Coupling Cyclization

Imidazole derivatives are critical building blocks in the synthesis of pharmaceuticals, fluorescent materials, and ligands. Despite the development of many strategies, the reliable synthesis of 2,4,5-substituted imidazoles remains heavily researched. In this study, we present a protocol for synthesizing 2,4,5-substituted imidazole-bearing methyl groups using A3-coupling cyclization with calcium carbide as the acetylene source, reacting with amidines and aldehydes. This methodology is characterized by several features, including the utilization of a solid alkyne source, readily accessible starting materials, and applicability to 34 examples.