Benzyl Alcohol → 3-benzyloxy-4-(4-ethylbenzyl)-5-methyl-1H-pyrazole

Participants

Reaction Steps

To a solution of 1,2-dihydro-4-(4-ethylbenzyl)-5-methyl-3H-pyrazol-3-one (synthesized as described in WO0116147; 1.0 g, 4.6 mmol), benzyl alcohol (600 mg, 5.5 mmol) and triphenylphosphine (1.46 g, 5.5 mmol) in tetrahydrofuran (30 mL), diethyl azodicarboxylate (40% in toluene, 5.1 mmol) was added dropwise under ice cooling. After stirring overnight at room temperature, the reaction mixture was concentrated and the resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=75:25 to 70:30) to give 3-benzyloxy-4-(4-ethylbenzyl)-5-methyl-1H-pyrazole (550 mg, 39%) as a colorless powder.

Provenance & Evidence