An alternative synthesis of benzobis(imidazolium) salts via a 'one-pot' cyclization/oxidation reaction sequence

摘要

Cyclization of N-aryl and N-alkyl 2,5-diamino-1,4-benzoquinonediimines using paraformaldehyde under acidic conditions followed by oxidation with catalytic amounts of Pd(OAc)(2) afforded their respective benzobis(imidazolium) salts in yields of 48-98%. A comparative solid-state study between a 2,5-diamino-1,4-benzoquinonediimine and its corresponding benzobis(imidazolium) dichloride was also performed. (c) 2006 Elsevier Ltd. All rights reserved.