反应详情

According to Scheme 1 Step 2: A solution of ethyl 2-((dimethylamino)methylene)-5-methyl-3-oxohexanoate (11.6 mmol, 2.64 g) and hydrazine (11.6 mmol, 1.47 mL) in EtOH (10 mL) was stirred for 1 hour at room temperature. After evaporation of the solvent, the resulting crude product was purified by flash chromatography over silica gel using cyclohexane/AcOEt (80:20) as eluent to yield ethyl 3-isobutyl-1H-pyrazole-4-carboxylate (8.66 mmol, 1.70 g, 75%) as a yellow oil.

1. customAfter evaporation of the solvent
2. customthe resulting crude product was purified by flash chromatography over silica gel