Pyridinium based ionic liquids as promoters for a green and selective synthesis of N-monomethylanilines

Pyridinium based ionic liquids derived from β-picoline and n-alkylbromides were synthesized by a simple procedure at ambient temperature and then characterized. These neutral ionic liquids were investigated for their dual role as the solvent and promoter for the selective synthesis of a series of N-monomethylanilines using dimethylcarbonate as the methylating agent. A solvent free green procedure was developed. Reaction conditions were mild and the product recovery was simple. Excellent selectivity for N-monomethylation, the high yield of the product and recyclability of the ionic liquids are some of the promising features of this protocol.