[CH:1]1([C:4]2[C:5]([N+:15]([O-:17])=[O:16])=[CH:6][C:7]([N+:12]([O-:14])=O)=[C:8]([CH:11]=2)[CH:9]=O)[CH2:3][CH2:2]1.[Cl:18][C:19]1[CH:25]=[CH:24][C:22]([NH2:23])=[CH:21][CH:20]=1.[C-:26]#[N:27].[Na+].C(OC(=O)C)(=O)C>C(O)(=O)C.CO>[Cl:18][C:19]1[CH:25]=[CH:24][C:22]([N:23]2[C:9]([C:26]#[N:27])=[C:8]3[C:7]([CH:6]=[C:5]([N+:15]([O-:17])=[O:16])[C:4]([CH:1]4[CH2:2][CH2:3]4)=[CH:11]3)=[N+:12]2[O-:14])=[CH:21][CH:20]=1To a stirred suspension of (iv) (20 g, 0.09 mol) in acetic acid (400 mL) was added 4-chloroaniline (21.6 g, 0.17 mol) and the reaction heated at 60° C. to obtain a complete solution. To this solution was added sodium cyanide (20 g, 0.41 mol) portionwise over 20 min. The reaction mixture was stirred for 5 min whereupon acetic anhydride (6 mL) was added. Upon the formation of a precipitate, an additional quantity of sodium cyanide (20 g, 0.41 mol) was added portionwise. After stirring for 1 h, the reaction mixture was cooled to RT, diluted with MeOH (30 ml) and the solids separated by filtration. The solid cake was dissolved in chloroform (400 ml) and the organics washed with water (2×100 ml), dried (MgSO4) and concentrated in vacuo to give the intermediate 2-(4-chlorophenyl)-5-cyclopropyl-6-nitro-2H-indazole-3-carbonitrile 1-oxide (34.6 g). ESI-MS m/z calculated for [M+H]+: 355.1. found: 355.2. 1H NMR (400 MHz, CDCl3) δ 8.32 (s, 1H), 7.72-7.50 (m, 5H), 2.44-2.30 (m, 1H), 1.18-1.05 (m, 2H), 0.85-0.71 (m, 2H).
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