5-Nitroindazole → 3-Chloro-5-nitro-1H-indazole

Participants

Reaction Conditions

Reaction Steps

5-Nitroindazole (5 g, 30.7 mmol) was suspended in glacial AcOH (150 mL) and the mixture heated to 50° C. N-Chlorosuccinimide (4.9 g, 36.8 mmol) was added and the mixture heated at relux (solution forms) for 1 hour. The reaction mixture was concentrated and partitioned between EtOAc and brine. The organic phase was washed with saturated sodium bicarbonate, dried over sodium sulfate and concentrated to a yellow solid. Recrystallisation from EtOH provided the title compound as a pale yellow solid (2.63 g, 43%); 1H NMR (400 MHz, DMSO) δ 7.73 (1H, d), 8.21 (1H, dd), 8.51 (1H, d), 13.97 (1H, brs); MS (ES−) m/e=196.

Provenance & Evidence