反应详情

9 g of 5-amino-1-phenyl-4-pyrazolecarbonitrile were stirred at 10°-15° C. with 40 ml of concentrated sulphuric acid until all of the solid had dissolved. The mixture was poured on to 150 g of crushed ice and made basic with concentrated ammonia solution. The precipitated product was filtered off and purified by chromatography on silica gel using 5% methanol in ethyl acetate for the elution. There were obtained 5.8 g of 5-amino-1-phenyl-4-pyrazolecarboxamide. A sample recrystallized from water melted at 163°-165° C.

1. dissolutionhad dissolved
2. filtrationThe precipitated product was filtered off
3. custompurified by chromatography on silica gel using 5% methanol in ethyl acetate for the elution