[N:1]([O-])=O.[Na+].[C:5]1([C:11]#[C:12][C:13]2[C:14]([C:19]([F:22])([F:21])[F:20])=[N:15][NH:16][C:17]=2[NH2:18])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.[ClH:23]>C(Cl)Cl>[Cl:23][C:12]1[C:11]([C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=2)=[N:1][N:18]=[C:17]2[NH:16][N:15]=[C:14]([C:19]([F:21])([F:22])[F:20])[C:13]=12To a cooled (cooling bath −15° C.) stirred suspension of sodium nitrite (540 mg, 7.8 mmol) in conc. HCl (20 mL) was added a solution of 4-(2-phenylethynyl)-3-(trifluoromethyl)-1H-pyrazol-5-amine (652 mg, 2.6 mmol) in CH2Cl2 (3 mL). The cooling bath was removed and the reaction mixture was stirred at room temperature for 1 h. NaCl (900 mg) was added and the reaction heated at 50° C. for 16 h. CH2Cl2 was added to the cooled reaction mixture. The aqueous phase was extracted with CH2Cl2 twice and the organic phases combined, dried over MgSO4, filtered and evaporated. The residue was purified by column chromatography (silica gel, ethyl acetate/isohexane 1:9 to 1:0) yielding the title compound as a yellow glass (115 mg) which was used in the subsequent step.
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