Synthesis
1. 1.6 mmol of 4-nitroimidazole (1a-e), 2.6 mmol of phenylboronic acid (2a-n), 1.6 mmol of sodium hydroxide, 0.2 mmol of CuCl2 and 15 mL of methanol were added to the reaction flask. 2. The reaction mixture was heated and refluxed under air bulge conditions. 3. The progress of the reaction was monitored by TLC, and after completion of the reaction the solvent was removed under reduced pressure using a rotary evaporator to remove the solvent under reduced pressure.4. The crude product was purified by silica gel column chromatography using 5:95 (v/v) methanol/chloroform as eluent to obtain the target product 4-nitro-1-phenylimidazole.5. The final product was purified by crystallization through a solvent mixture of methanol/water.
References
[1] Beilstein Journal of Organic Chemistry, 2013, vol. 9, p. 1517 - 1525
[2] Patent: WO2017/109488, 2017, A1. Location in patent: Page/Page column 41
[3] Patent: WO2018/65768, 2018, A1. Location in patent: Page/Page column 89
