Potassium Carbonate → 4-Ethynyl-1-(4-fluorophenyl)-2-methyl-1H-imidazole

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Reaction Steps

(1-Diazo-2-oxo-propyl)-phosphonic acid dimethyl ester (6.51 g, 33.9 mmol) was dissolved in 100 mL methanol. Potassium carbonate (7.81 g, 56.5 mmol) was added. A solution of 1-(4-fluoro-phenyl)-2-methyl-1H-imidazole-4-carbaldehyde (5.77 g, 45 mmol) in 100 mmol methanol was added dropwise at RT. The reaction mixture was stirred at RT overnight. The solvent was evaporated. The residue was taken up in 150 mL water and extracted three times with ethyl acetate (150 mL each). The combined organic extracts were dried with sodium sulfate, filtered and evaporated. The crude product was purified by flash chromatography on silica gel (heptane/ethyl acetate 100:0→0:100 gradient) and the desired compound was obtained as a white solid (3.81 g, 67%), MS: m/e=200.1 (M+). 1-(3,4-Dichloro-phenyl)-4-ethynyl-2-methyl-1H-imidazole (IV-2) [MS: m/e=252.1 (M+)] was prepared in accordance with the method of example IV-1 from 3,4-dichloroaniline.

Provenance & Evidence