Anthracene Amines from Benzyne and Imidazole

Significance

Three equivalents of benzyne react with N-substituted imidazoles to produce various anthracene-containing amines. The authors note that it has previously been reported that similar reaction conditions yield N-alkyl-N′-aryl imidazolium salts from the nucleophilic addition of imidazole to benzyne followed by protonation. Those reactions were performed with a three-fold excess of imidazole derivative, whereas the current transformation is achieved with excess benzyne at higher temperatures.