Synthesis
1. To a 1 L round bottom flask was added a dioxane solution (400 mL) of 1-bromo-3-iodobenzene (18.20 g, 64.3 mmol), 1H-pyrazole (4.38 g, 64.3 mmol), and (1S,2S)-cyclohexane-1,2-diamine (1.5 g, 12.9 mmol).
2. cuprous iodide (I) (0.613 g, 3.22 mmol) and potassium carbonate (17.78 g, 129 mmol) were added and the reaction mixture was stirred under reflux conditions for 19 hours.
3. After completion of the reaction, the crude mixture was filtered through a diatomaceous earth pad.
4. The filtrate was diluted with 400 mL of dichloromethane and washed with deionized water.
5. The organic layer was separated, concentrated and purified by silica gel column chromatography using a hexane solution of 5% ethyl acetate as eluent to give 7.3 g (51% yield) of 1-(3-bromophenyl)-1H-pyrazole as a white solid.
6. Subsequently, the synthesis of N-(3-(1H-pyrazol-1-yl)phenyl)-3-(1-(2,6-dimethylphenyl)-1H-imidazol-4-yl)-N-phenylaniline was carried out.
References
[1] Patent: KR101897044, 2018, B1. Location in patent: Paragraph 0444-0445; 0448-0450
[2] Patent: EP2574613, 2013, A1. Location in patent: Paragraph 0144
