2-Methylimidazole → 4-[3-(2-methyl-1H-imidazol-1-yl)propyl]-1-piperidinecarboxaldehyde

A mixture of 2-methylimidazole (2 g, 0.025 M) and sodium hydride (1.2 g, 50% in mineral oil, 0.025 M) in dimethylformamide (20 ml) was stirred at room temperature for 1/2 hr. The reaction mixture was then heated at 50° C. and the solution of 4(3-bromopropyl)piperidine carboxaldehyde (4.6 g, 0.02 M) in dimethylformamide (20 ml) was added slowly. After completing the addition, the reaction was heated at 50° C. for 4 hrs and then solvent was removed in vacuo. Water (80 ml) was added to the residue and the mixture was extracted with methylene chloride. The combined extracts, dried over sodium sulfate, were stripped to dryness to yield an oil. The oil was purified on silica gel column, eluted with methanol chloroform (1:9 v/v) to give 4-[3-(2-methyl-1H-imidazol-1-yl)-propyl]-1-piperidinecarboxaldehyde (3.86 g, 88% yield).