1-Benzyl-5-nitro-1H-indazole → 1-(Phenylmethyl)-1H-indazol-5-amine

Participants

Reaction Steps

7.61 g (136 mmol, 5 equiv) of Iron powder (4.03 g, 72.1 mmol) was added slowly to the solution of 1-Benzyl-5-nitro-1H-indazole (6.9 g, 27.2 mmol) in acetic acid (200 mL). After stirring at room temperature overnight, the reaction mixture became milky with formation of a white precipitate. The precipitate was filtered off and the filtrate was concentrated to ca. 20 mL. The residue was diluted with water (200 mL) and neutralized by slow addition of sodium hydroxide. The mixture was then extracted with ethyl acetate (500×5 mL). The organic layer were combined, dried over sodium sulfate, filtered and concentrated to dryness to afford 1-benzyl-1H-indazol-5-ylamine (5.23 g, 82%) as a brown solid. 1H NMR (DMSO-d6): δ 7.72 (s, 1H), 7.35 (d, J=8.8 Hz, 1H), 7.24–7.14 (m, 5H), 6.74 (m, 2H), 5.49 (s, 2H), 4.80 (br, 2H). ES-LCMS: RT=0.93 min; [M+H]+=224.2.

Provenance & Evidence