[Br:1][C:2]1[C:3]2[N:11]([CH2:12][CH3:13])[C:10]([C:14](=[N:17][OH:18])[C:15]#[N:16])=[N:9][C:4]=2[C:5]([Cl:8])=[N:6][CH:7]=1.C([N:21](CC)CC)C.NO>O1CCOCC1.CO>[Br:1][C:2]1[C:3]2[N:11]([CH2:12][CH3:13])[C:10]([C:14]3[C:15]([NH2:21])=[N:16][O:18][N:17]=3)=[N:9][C:4]=2[C:5]([Cl:8])=[N:6][CH:7]=1To a mixture of (7-bromo-4-chloro-1-ethyl-1H-imidazo[4,5-c]pyridin-2-yl)hydroxyimino-acetonitrile (V, 545 g, 1.45 mol) in dioxane (5 L) was added triethylamine (1 L) and hydroxylamine (143 g, 55% in water). The reaction was heated at reflux for 6 h. After cooling the reaction to ambient temperature, the mixture was filtered and the filtrate concentrated under reduced pressure to give a brown solid. The solid was suspended in methanol (1 L) and the suspension was stirred at 65° C. for 0.5 h. The solid was collected by filtration and dried to give 321 g (70% yield) of the desired compound (VI). This was used in the next step without further purification. MS (ES+) m/z 343 (M+H)+.
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