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

HRID 1711697Notes

Reaction equation

F[C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:12]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])=[CH:11][C:10]([CH:20]([CH3:22])[CH3:21])=[N:9]2)=[CH:4][C:3]=1[N+:23]([O-:25])=[O:24].[Li+].[OH-].OO.[O-:30]S([O-])(=S)=O.[Na+].[Na+]>C1COCC1.O.C(O)(=O)C>[OH:30][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:12]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])=[CH:11][C:10]([CH:20]([CH3:22])[CH3:21])=[N:9]2)=[CH:4][C:3]=1[N+:23]([O-:25])=[O:24]

Participants

Conditions

Temperature: 60 °C

Procedure

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+).

Workup

extractionThe solution was extracted with EtOAc
washthe organic layer was washed with brine
dry with materialdried (MgSO4)
concentrationconcentrated in vacuo
custompurified by silica gel column chromatography (EtOAc/hexanes)

Sources & evidence

ORD record: ord-e2ce8b04716b4bc29ae554f32bb46027
Source dataset: uspto-grants-2010_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07790756B2

Reaction notes

Loading…