[NH2:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[C:4]([CH2:13][C:14]#[N:15])[C:3]=1[C:16]#[N:17].[CH3:18][O:19][C:20]1[CH:27]=[CH:26][CH:25]=[C:24]([O:28][CH3:29])[C:21]=1[CH:22]=O.N1CCCCC1>C1(C)C=CC=CC=1>[NH2:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[C:4]([C:13]([C:14]#[N:15])=[CH:22][C:21]2[C:24]([O:28][CH3:29])=[CH:25][CH:26]=[CH:27][C:20]=2[O:19][CH3:18])[C:3]=1[C:16]#[N:17]1 g (4.48 mmol) of 5-amino-4-cyano-1-phenyl-3-pyrazoleacetonitrile is suspended in 15 mL of toluene, in a round-bottomed flask, under an argon atmosphere, surmonted by a Dean and Stark apparatus. 0.744 g (1 eq.) of 2,6-dimethoxybenzaldehyde and 0.030 mL of piperidine are added to the mixture. The reaction medium is refluxed overnight, and is then allowed to return to ambient temperature. A whitish precipitate forms and is filtered off and washed with toluene. The filtrate is concentrated to dryness and the residue is taken up in ethanol with agitation for 15 minutes. The suspension is filtered and the filtrate is concentrated to dryness. The residue is combined with the precipitate previously obtained, and purified on silica gel (eluent: 98/2 dichloromethane/methanol). 619 mg of product are thus obtained with a yield of 37%.
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