反应详情

A mixture of 2-hydrazino-5-methyl-1H-benzimidazole (4) (1.0 g) and ethyl 2-acetyl-3-phenylpropanoate (1.4 mL) in acetic acid (20 mL) was stirred at room temperature for 2 hr. The reaction mixture was added to a mixture of acetonitrile (100 mL) and water (100 mL). After stirring at room temperature, the resulting precipitate was collected by filtration, and washed with a mixture of acetonitrile and water (1:1). The precipitate was recrystallized from ethanol (95 mL) to give 3-methyl-1-(5-methyl-1H-benzimidazol-2-yl)-4-(phenylmethyl)-1H-pyrazol-5-ol (5) (0.64 g).

1. stirringAfter stirring at room temperature
2. filtrationthe resulting precipitate was collected by filtration
3. washwashed with a mixture of acetonitrile and water (1:1)
4. customThe precipitate was recrystallized from ethanol (95 mL)