5334-31-6

16617-46-2

5334-31-6

General procedure for the synthesis of 3-aminopyrazole-4-carboxamide from 3-amino-4-cyanopyrazole: 5-amino-1H-pyrazole-4-carbonitrile (1) (5 g, 0.046 mol) was slowly added to pre-cooled concentrated sulfuric acid (10 ml) under stirring conditions, and the temperature of the reaction was controlled not to exceed 20 °C. After the addition was completed, the reaction mixture was stirred continuously at room temperature for 4 hours. Subsequently, the reaction solution was slowly poured into ice water under stirring and the mixture was allowed to stand in a refrigerator overnight. The precipitated solid product was collected by filtration and washed with water to remove residual sulfuric acid, which ultimately yielded the target compound 5-amino-1H-pyrazole-4-carboxamide (2) as a white solid with a yield of 5.19 g in 89% yield; melting point 220-222 °C (literature value 222-225 °C) [33].