Nitric Acid → 1,3-Dinitro-1H-pyrazole

Participants

Reaction Steps

To a stirred mixture of 3-nitro-1H-pyrazole (3.16 g, 27.9 mmol) in glacial acetic acid (20 mL) at 0° C. was added fuming nitric acid (2.6 mL, 58.69 mmol) dropwise, followed by acetic anhydride (6.6 mL, 69.87 mmol). The mixture was stirred and allowed to warm to rt over 3 h, then poured into ice water (50 mL) and stirred for 20 h. The mixture was extracted with EtOAc combined organic layers were dried over MgSO4, filtered and concentrated to dryness to afford 1,3-dinitro-1H-pyrazole (4.3 g, 97%). 1H NMR (300 MHz, DMSO-d6) δ 8.00 (br s, 1H), 6.44 (br s, 1H).

Provenance & Evidence