General method: 4-Iodo-1,3-dimethyl-1H-pyrazole (1 mmol) was dissolved in tetrahydrofuran (THF, 10 mL) and Fuajasite catalyst (250 mg) was added. Concentrated nitric acid (density 1.52 g/cm3, 10 mL) was added slowly and the reaction was stirred at room temperature for the desired time. After completion of the reaction, the catalyst was recovered by filtration and the filtrate was extracted with dichloromethane several times. The organic phases were combined and concentrated under reduced pressure to remove the solvent to give 1,3-dimethyl-4-nitro-1H-pyrazole.
[1] Synthetic Communications, 2012, vol. 42, # 23, p. 3463 - 3471
[2] Russian Chemical Bulletin, 1996, vol. 45, # 11, p. 2581 - 2584
[3] Catalysis Communications, 2013, vol. 42, p. 35 - 39