Synthesis of 4,4'-biimidazoles

Article abstract of DOI:10.1055/s-1994-25544

The palladium(0) catalysed coupling reaction of 4-iodo-1-triphenylmethylimidazole (7) or its 2-methyl analogue 8 afforded the 4,4'-biimidazoles 9 and 10, respectively. Treatment of these compounds with 60% aqueous trifluoroacetic acid gave 4,4'-biimidazole and 2,2'-dimethyl-4,4'-biimidazole as their bistrifluoroacetate salts 11 and 12, respectively.