Hydrochloric Acid → 5-Methyl-3-(3-methyl-4-nitrophenyloxy)pyrazole

HRID 644829Notes

Reaction equation

C(=O)([O-])[O-].[K+].[K+].[OH:7][C:8]1[CH:12]=[C:11]([CH3:13])[NH:10][N:9]=1.F[C:15]1[CH:16]=[CH:17][C:18]([N+:22]([O-:24])=[O:23])=[C:19]([CH3:21])[CH:20]=1.Cl>CN(C=O)C>[CH3:13][C:11]1[NH:10][N:9]=[C:8]([O:7][C:15]2[CH:16]=[CH:17][C:18]([N+:22]([O-:24])=[O:23])=[C:19]([CH3:21])[CH:20]=2)[CH:12]=1

Participants

Conditions

Temperature: 70 °C

Procedure

Potassium carbonate (2.23 g, 16.1 mmol) was added to a solution of 3-hydroxy-5-methylpyrazole (3.16 g, 32.2 mmol) and 5-fluoro-2-nitrotoluene (5.00 g, 32.2 mmol) in DMF (50 ml), and the mixture was stirred at 70° C. for 3 hours. After completion of the reaction, a reaction mixture was poured into 2N hydrochloric acid (50 ml) and extracted with ethyl acetate (30 ml×2). An organic layer was washed with water (50 ml×3), dried over anhydrous magnesium sulfate and filtered to remove a desiccant, and the solvent was distilled off from the filtrate under reduced pressure. The resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/3), to give a yellowish solid of 5-methyl-3-(4-nitro-3-methylphenyloxy)pyrazole (2.51 g, yield: 27.8%). mp: 114-117° C.; 1H-NMR (CDCl3, TMS, ppm): δ 2.30 (d, J=0.5 Hz, 3H), 2.61 (s, 3H), 5.72 (d, J=0.5 Hz, 1H), 6.98-7.04 (m, 2H), 8.05 (d, J=9.8 Hz, 1H), 10.12 (br s, 1H).

Workup

customAfter completion of the reaction
extractionextracted with ethyl acetate (30 ml×2)
washAn organic layer was washed with water (50 ml×3)
dry with materialdried over anhydrous magnesium sulfate
filtrationfiltered
customto remove a desiccant, and the solvent
distillationwas distilled off from the filtrate under reduced pressure
customThe resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/3)

Sources & evidence

ORD record: ord-d33bc08852504188848c86f364b3de6e
Source dataset: uspto-grants-2010_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07700786B2

Reaction notes

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