A mild nitration of pyrrolo[2,1-a]isoquinolines has been reached in a NaNO₂/HFIP reaction system.

Abstract

A mild nitration of pyrrolo[2,1-a]isoquinolines has been reached using sodium nitrite as nitro source in HFIP at ambient temperature. A variety of nitro-bearing pyrrolo[2,1-a]isoquinoline derivatives has been efficiently prepared in poor to quantitative yields (28–98 %). These products can be easily transformed to primary amines and amide by simple chemical reactions. Treatment of other nitrogen-containing heterocycles such as pyrrolo[1,2-a]quinoline and substituted indoles under this developed reaction system afforded nitro-bearing N-heterocycles in relatively lower yields (15–19 %).