Regioselective and solvent-free arylation of β-nitrostyrenes with mono- and dialkyl anilines

A green and solvent-free method were developed for alkylation of N,N-dialkylanilines with substituted β-nitrostyrenes using 10 mol% of choline chloride-zinc chloride deep eutectic solvent at 70 °C. The reaction was highly regioselective and only para-substituted products have been prepared. Despite the sensitivity and weak reactivity of the aniline derivatives for the Friedel–Crafts reaction in acidic media, the presented procedure was successfully carried out this transformation. The synthetic protocol was expanded for the alkylation of pyrrole and indole to produce pharmaceutically active compounds. The reduction of the nitro group of the product to amine was performed using Pd/C and hydrazine to produce amphetamine structure.