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.

Automated summary

This study presents 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.