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4-Aminopyrazole, is a versatile building block for the preparation of pharmaceutical and biologically active compounds. 4-Amino-1H-pyrazole, has also shown to have anticonvulsant activity, and thus can be used in the treatment of epileptic seizures.

4-Nitropyrazole (1.13 g, 10 mmol) was dissolved in methanol (10 mL) under hydrogen (1 atm) atmosphere and 10% Pd-C catalyst (0.1 g) was added. The reaction mixture was stirred at 25 °C for 12 hours. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to afford the target product 4-aminopyrazole (860 mg, yield: 100%), which could be used in subsequent reactions without further purification.

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