4-nitro-1H-pyrazole → 1-(Cyclopropylmethyl)-4-nitro-1H-pyrazole

Participants

Reaction Steps

To a solution of 4-nitro-1H-pyrazole (5.05 g, 44.7 mmol) in N,N-dimethylformamide (250 mL) was added sodium hydride (2.7 g, 68 mmol, 60% mineral oil suspension) at 0° C. in portions and then followed by bromomethylcyclopropane (6.5 mL, 67 mmol) dropwise at same temperature. The mixture was stirred at room temperature for 4 h and diluted with water (300 mL) and extracted with EtOAc (300 mL×3). The combined organic phases were washed with brine (500 mL), dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (EtOAc/PE (v/v)=1/50 to 1/20) to give the product as yellow oil (7.38 g, 98.9%).

Provenance & Evidence