Potassium Carbonate → methyl 1-methyl-2-phenyl-1H-imidazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl-2-bromo-1-methyl-1H-imidazole-5-carboxylate (1 g, 4.56 mmol) and phenylboronic acid (0.67 g, 5.48 mmol) were dissolved in toluene-EtOH (80 mL, 5:3 v/v) and the solution was purged with argon for 10 min. K2CO3 (10 mL, 2M solution) and catalytic PdCl2(dppf) (82 mg, 0.12 mmol) were added and the reaction mixture was heated to 100° C. for 1 h. The reaction mixture was then cooled to room temperature and concentrated under reduced pressure. The residue was diluted with water and washed with EtOAc. The aqueous layer was acidified to pH ˜6 using 1.5N HCl and the crude product was extracted with EtOAc. The combined extracts were dried over anhydrous Na2SO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica 60-120 mesh, eluent 35-45% EtOAc in petroleum ether) to get methyl 1-methyl-2-phenyl-1H-imidazole-5-carboxylate (800 mg, yield 81%) as a pale yellow solid. 1H NMR (400 MHz, CDCl3) δ 7.86 (s, 1H), 7.63-7.61 (m, 2H), 7.51-7.48 (m, 3H), 3.96 (s, 3H), 3.89 (s, 3H). MS (ESI) m/z: Calculated for C12H12N2O2: 216.09. found: 2168.8 (M+H)+.

Provenance & Evidence