Acetic Acid → 3-tert-butyl-1-(4-nitrophenyl)-1H-pyrazol-5-amine

Participants

Reaction Steps

To a solution of 4,4-dimethyl-3-oxopentanenitrile (20.4 g, 163 mmol) and 4-nitrophenylhydrazine (25.0 g, 163 mmol) in anhydrous EtOH (300 mL) was added acetic acid (3.4 mL, 60 mL) dropwise. The reaction was stirred at reflux under N2 for 18 h. The reaction mixture was cooled to room temperature and concentrated at reduced pressure. The residue was partitioned between EtOAc (500 mL) and aqueous saturated NaHCO3 solution (300 mL). The organic layer was washed with water and brine, dried over Na2SO4, and concentrated at reduced pressure. The crude residue was purified by MPLC (eluting with 80:20 hexanes/EtOAc) to give 36.0 g (85%) of the desired product. 1H-NMR (DMSO-d6) δ 8.28 (d, J=6.9 Hz, 2H), 7.93 (d, J=6.9 Hz, 2H), 5.55 (s, 2H), 5.46 (s, 1H), 1.20 (s, 9H); MS LC-MS [M+H]+=261, RT=2.74 min.

Provenance & Evidence