1-Bromopropane → 3-nitro-1-propyl-1H-pyrazole

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Reaction Steps

3-Nitro-1H-pyrazole (prepared in example 3, 100 mg, 0.89 mmol) was dissolved in anhydrous N,N-dimethylformamide (4 mL) and a 60% dispersion of sodium hydride in mineral oil (37 mg, 0.93 mmol) was added while stirring under nitrogen. After the effervescence ceased and the mixture was stirred for an additional 10 min, the 1-bromo-propane (91 μL, 1.00 mmol) was added. The mixture was continued to stir under nitrogen for 16 h. The solution was diluted with ethyl acetate (50 mL), washed with water (2×20 mL), saturated aqueous brine solution (2×20 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 10 g; 25% ethyl acetate/hexanes to 75% ethyl acetate/hexanes) afforded 3-nitro-1-propyl-1H-pyrazole (92 mg, 67%) as a yellow oil: H1-NMR (400 MHz, CDCl3) δ0.89 (3H, t, J=7.6 Hz), 1.90 (2H, sextet, J=7.2 Hz), 6.82 (1H, d, J=2.8 Hz), 7.44 (1H, d, J=2.4 Hz).

Provenance & Evidence