Ligands for M-NHC Synthesis  : Continuous Flow Di-N-Alkylation of 1H-Benzimidazole in a fixed Bed Reactor

The successful transfer from batch to a continuous flow process in a fixed bed reactor of a ligand in metalorganic API synthesis, the diazolium salt 1,3-methyl-benzoimidazol-3-ium iodide, is presented. Results show similar yields and conversion rates at corresponding process parameters in batch and continuous mode. By exceeding temperature limitation of a non-pressurized batch process, the pressurized continuous reactor system shows the potential for outperforming the batch synthesis regarding space time yield. Hence, process intensification by continuous flow presents itself as a viable approach for the heterogeneous di-N-alkylation of diazoles. Alternative basic reagents and solvents further enhance the viability of a continuous approach by addressing limitations such as side reactions and solubility of the reagent.