Isopropyl iodide → 3-benzyloxy-4-(4-ethylbenzyl)-1-isopropyl-5-methyl-1H-pyrazole

Participants

Reaction Steps

To a suspension of the thus obtained 3-benzyloxy-4-(4-ethylbenzyl)-5-methyl-1H-pyrazole (200 mg, 0.65 mmol) and cesium carbonate (1.06 g, 3.25 mmol) in N,N-dimethylformamide (4 mL), isopropyl iodide (350 mg, 2.06 mmol) was added dropwise at room temperature. After stirring at room temperature for 13 hours, additional cesium carbonate (1.06 g, 3.25 mmol) and isopropyl iodide (350 mg, 2.06 mmol) were added. After stirring at room temperature for an additional 3 hours, the reaction mixture was diluted with water and extracted with ethyl acetate. The resulting organic layer was washed with saturated aqueous sodium chloride and dried over anhydrous magnesium sulfate. After the solvent was distilled off under reduced pressure, the resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1) to give 3-benzyloxy-4-(4-ethylbenzyl)-1-isopropyl-5-methyl-1H-pyrazole (179 mg, 79%) as a light-brown oil.

Provenance & Evidence