[NH2:1][C:2]1[N:3]([C:13](=[O:15])[NH2:14])[N:4]=[CH:5][C:6]=1[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[C:16](OC)(=O)C>C([O-])([O-])OCC>[OH:15][C:13]1[N:3]2[N:4]=[CH:5][C:6]([C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=3)=[C:2]2[N:1]=[CH:16][N:14]=1A mixture of 3-amino-2-carbamoyl-4-phenylpyrazole (4.8 g) and ethyl orthoformate (30 ml) is stirred at 100°-110° C. for 13 hours, and thereto is added methanol acetate. The precipitate is separated by filtration, washed with methanol or ethyl acetate, and dried to give the title compound (2.08 g).
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