反应详情

To a solution of 3-nitro-1H-pyrazole (prepared in example 3, 200 mg, 1.77 mmol) in anhydrous N,N-dimethylformamide (2 mL), a 60% dispersion of sodium hydride in mineral oil (92 mg, 2.30 mmol) was added while stirring under nitrogen. After the effervescence ceased and the mixture was stirred for additional 10 min, benzylbromide (273 μL, 2.33 mmol) was added. The mixture was continued to stir under nitrogen for an additional 2 h. The solvent was removed in vacuo and purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 2% methanol/methylene chloride to 5% methanol/methylene chloride) afforded 1-benzyl-3-nitro-1H-pyrazole (303 mg, 84%) as a white solid: H1-NMR (400 MHz, CDCl3) δ: 5.33 (2H, s), 6.84 (1H, d, J=2.7 Hz), 7.26 (2H, m), 7.32 (3H, m), 7.40 (1H, d, J=1.5 Hz).

1. stirringthe mixture was stirred for additional 10 min
2. stirringto stir under nitrogen for an additional 2 h
3. customThe solvent was removed in vacuo and purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 2% methanol/methylene chloride to 5% methanol/methylene chloride)