Water → 5-Nitro-3-phenyl-1H-indazole

Participants

Reaction Steps

To a solution of 2-chloro-5-nitrobenzophenone (15 g, 57 mmol) in ethanol (300 mL) was added hydrazine monohydrate (50 mL, 1 mol). The resultant solution was stirred overnight (16 hrs.) at ambient temperature, then poured into water (2 L) and stirred for an additional 2 hours. The precipitate that formed was collected by filtration, washed with water (2×100 mL) and air dried to give 5-Nitro-3-phenyl-1H-indazole 11a (13.1 g, 80%) as a yellow solid: 1H NMR (DMSO-d6) δ 7.48 (tt, 1H, J=1.3, 7.4 Hz), 7.58 (dd, 2H, J=7.1, 7.4 Hz), 7.78 (d, 1H, J=9.2 Hz), 8.01 (dd, 2H, J=1.3, 7.1 Hz), 8.25 (dd, 1H, J=2.1, 9.2 Hz), 8.91 (d, 1H, J=2.1 Hz), 13.88 (s, 1H). Anal. (C13H9N3O2) C, H, N.

Provenance & Evidence