Hydrogen Peroxide → tert-butyl 1-(4-hydroxy-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 1-(4-fluoro-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylate (0.74 g, 2.1 mmol) in THF/water (12 mL) was added LiOH (300 mg, 13 mmol) and H2O2 (30% wt, 0.96 mL). The reaction mixture was heated overnight at 60° C. Na2S2O3 solution was added until the peroxide test (starch-iodide paper) was negative. Acetic acid was added until the pH was 4-5. The solution was extracted with EtOAc and the organic layer was washed with brine, dried (MgSO4), concentrated in vacuo and purified by silica gel column chromatography (EtOAc/hexanes) to obtain tert-butyl 1-(4-hydroxy-3-nitrophenyl)-3-isopropyl-1H-pyrazole-5-carboxylate (0.27 g, 37% yield). MS (ESI) m/z: 348.3 (M+H+).

Provenance & Evidence