[NH2:1][C:2]1[C:3]([CH3:10])=[N:4][N:5]([CH3:9])[C:6]=1[C:7]#[N:8].[CH:11](OC(=O)C)=[O:12]>>[C:7]([C:6]1[N:5]([CH3:9])[N:4]=[C:3]([CH3:10])[C:2]=1[NH:1][CH:11]=[O:12])#[N:8]The starting material is obtained by treating 16 g (0.12 mol) of 4-amino-5-cyano-1,3-dimethyl pyrazole [U.S. Pat. No. 3,121,092: CA 60 2030 (1964)] with acetic-formic anhydride (prepared by adding 45 ml of acetic anhydride to 20 ml of 98% formic acid at 50° C.). After standing at room temperature overnight, the solution is evaporated in vacuo. The residue is stirred in ether to give 14.5 g (74%) of N-(5-cyano-1,3-dimethylpyrazol-4-yl) formamide, mp 135° C.
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