General procedure for the synthesis of 3,5-dimethyl-4-nitropyrazole from 3,5-dimethyl-4-iodopyrazole:
1. 3,5-dimethyl-4-iodopyrazole (1 mmol) was dissolved in tetrahydrofuran (THF, 10 mL).
2. Add Fuajasite catalyst (250 mg) to the above solution.
3. Concentrated nitric acid (density 1.52 g/cm3, 10 mL) was added slowly.
4. Stir the reaction mixture at room temperature until the reaction is complete. 5.
5. Upon completion of the reaction, the catalyst was filtered to recover the catalyst. 6.
6. The filtrate was extracted several times with dichloromethane. 7.
7. The organic phases were combined and concentrated in vacuum to remove the solvent to give 3,5-dimethyl-4-nitropyrazole.
