2,6-Diamino-4-chloropyrimidine 1-oxide-Assisted Copper-CatalyzedSynthesis of N-Arylimidazoles in Water

To achieve the Ullmann reaction in water, 2, 6-diamino-4-chloropyrimidine 1-oxide, an inexpensive and good biocompatibility drug, was used as a ligand to promote the CuBr-catalyzed reaction between aryl halides and imidazole, yielding a series of N-arylimidazoles in good yields. Coordination of 2, 6-diamino-4-chloropyrimidine 1-oxide with CuBr formed dissolvable complexe and well activated reactant. This coupling strategy enables gram-scale synthesis of 1-(4- methoxyphenyl)-1H-imidazole and is suitable for preparing biphenyl, 1,4-diphenylbutadiyne, and 2- phenylindole. Overall, it provides a simple and efficient method to synthesize N-arylimidazoles.