68703-67-3

61241-07-4

68703-67-3

The general procedure for the synthesis of 4-amino-1H-pyrazole-3-carbonitrile from 4-nitro-1H-pyrazole-3-carbonitrile was as follows: 4-nitro-1H-pyrazole-3-carbonitrile (7.24 mmol) was dissolved in methanol (200 mL), 10% Pd/C catalyst was added (catalyst dosage of 10% of the mass of the raw material w/w), and hydrogenation was carried out in the Parr hydrogenation unit at 30 psi hydrogen pressure for 24 hours. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to give a dark brown solid product. The product was pure enough to be used directly in the subsequent reaction in 90% yield. The structure of the product was confirmed by 1H NMR (DMSO-d6): δ 4.6 (broad peak, 2H, NH2), 7.22 (single peak, 1H, H-5), 13.1 (broad peak, 1H, NH).