Novel oxidative routes to N-arylpyridoindazolium salts

Abstract

A novel facile approach to N-arylpyridoindazolium salts is proposed, based on direct oxidation of the ortho-pyridine substituted diarylamines, either using bis(trifluoroacetoxy)iodobenzene as an oxidant, or electrochemically, via potentiostatic oxidation. Electrochemical synthesis occurs under mild conditions; no chemical reagents are required except electric current. Both approaches can be considered as a late-stage functionalization; easily available ortho-pyridyl-substituted diarylamines are used as the precursors.

Keywords

• anodic oxidation
• diarylamines
• electrochemical cyclization
• pyridoindazolium salts
• reversible ring closure