Azetidine → 5-(Azetidin-1-ylmethyl)-1-methyl-3-nitro-1H-pyrazole

To a solution of 5-(bromomethyl)-1-methyl-3-nitro-1H-pyrazole (436 mg, 1.98 mmol) in tetrahydrofuran (10 mL) was added azetidine (141 mg, 0.17 mL, 2.48 mmol) and diisopropylethyl amine (307 mg, 0.42 mL, 2.38 mmol) drop wise and the resulting mixture was stirred at room temperature for 24 h. The solution was concentrated and the residue dissolved in dichloromethane (50 mL), washed with water (50 mL). The aqueous layer was extracted with methylene chloride (2×50 mL) and the organic phases combined and dried over magnesium sulfate. The resulting mixture was filtered and evaporated and the residue purified by flash chromatography (40 g, 1% to 5% methanol in dichloromethane) to give 5-(azetidin-1-ylmethyl)-1-methyl-3-nitro-1H-pyrazole (349 mg, 90%) as a colorless oil.