N-Methyl-1H-benzo[d]imidazol-2-amine was synthesized as follows: 2-chloro-1H-benzo[d]imidazole (20 g, 131.08 mmol) was placed in an autoclave PV10832 (made of Hastelloy, 450 mL), and methylamine (260 mL, 131.08 mmol) was added and sealed. The reaction mixture was heated to 160°C in an autoclave oven for 16 hours. The pressure in the autoclave reached 11 bar during the reaction. After completion of the reaction, the solvent was removed by distillation under reduced pressure to give a brown oily substance. Ethanol (EtOH) was added to the oil and the solvent was again removed by distillation under reduced pressure to give a brown foamy product. The foamy product was dissolved in a minimal amount of hot acetone and subsequently cooled to room temperature. The precipitated solid was filtered to afford the target product N-methyl-1H-benzo[d]imidazol-2-amine (9.91 g, 51% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 2.83 (3H, s), 6.87-7.00 (2H, m), 7.05-7.25 (2H, m), 7.49 (1H, s).
