Nitro compounds, aromatic, reductive cyclization with triethyl phosphite

Nitro compounds, aromatic, reductive cyclization with triethyl phosphite, 48, 115... 

This reaction can be traced back to the initial work of Cadogan for the preparation of car-bazole by the reductive cyclization of aromatic nitro compounds with triethyl phosphite. This reaction was then extended by Sundberg to the fornnation of indoles by the treatment of o-nitrostyrene with triethyl phosphite or the formation of indolines from the o-alkyl nitrobenzenes. Thus the formation of indole from the reduction of o-nitfostyrenes is referred to as the Cadogan-Sundberg indole synthesis." ... 

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