反应详情

温度

90 °C

A solution of 5-amino-4-cyano-1-n-propylpyrazole (J. Med. Chem., 1968, 11, 79; 4.0 g, 0.0027 mol) in a mixture of concentrated sulphuric acid (30 ml) and water (3 ml) was heated at 90° C. for 1 hour. The cool reaction mixture was poured into ice/water (70 g) and the resulting mixture basified with solid sodium carbonate to pH 8. The aqueous solution thus obtained was extracted with ethyl acetate (5×100 ml), the combined extracts dried (Na2SO4) and the solvent removed by evaporation under vacuum to give the title compound as a pale yellow solid (4.25 g, 95%). A sample was obtained as colourless crystals, m.p. 183-185° C., by crystallisation from methanol-diethyl ether. Found: C, 50.39; H, 6.94; N, 33.21. C7H12N4O requires C, 49.99; H, 7.19; N, 33.31%.

1. customThe cool reaction mixture
2. customThe aqueous solution thus obtained
3. extractionwas extracted with ethyl acetate (5×100 ml)
4. dry with materialthe combined extracts dried (Na2SO4)
5. customthe solvent removed by evaporation under vacuum