Potassium Carbonate → Ethyl 1-phenyl-3-(trifluoromethyl)-1H-pyrazole-4-carboxylate

HRID 557717Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[C:7]([C:11]([F:14])([F:13])[F:12])=[N:8][NH:9][CH:10]=1)=[O:5])[CH3:2].C(=O)([O-])[O-].[K+].[K+].I[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1.CN[C@@H]1CCCC[C@H]1NC>C1(C)C=CC=CC=1.C(OCC)(=O)C.[Cu]I>[CH2:1]([O:3][C:4]([C:6]1[C:7]([C:11]([F:13])([F:14])[F:12])=[N:8][N:9]([C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)[CH:10]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: 110 °C

Procedure

A mixture of 3-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.5 g, 12.0 mmol), copper (I) iodide (0.69 g, 3.6 mmol) and potassium carbonate (3.49 g, 25.3 mmol) in toluene (12 mL) in a round bottom flask was purged with argon. To the reaction mixture was then added iodobenzene (1.61 mL, 14.4 mmol) and racemic trans-N,N′-dimethyl-cyclohexane-1,2-diamine (1.16 mL, 7.2 mmol). The slurry was heated under Ar in an oil bath at 110° C. for 24 hours. After cooling to room temperature, the reaction mixture was diluted with ethyl acetate and filtered over a bed of celite. The organic washings were combined and concentrated to give a crude which was purified by silica gel chromatography (Isco 120 g column, 0→30% ethyl acetate/hexanes) to give 1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.91 g, 85%) as an off-white solid. The NMR spectrum obtained on the sample is compatible with its structure.

Workup

customwas purged with argon
temperatureAfter cooling to room temperature
filtrationfiltered over a bed of celite
concentrationconcentrated
customto give a crude which
customwas purified by silica gel chromatography (Isco 120 g column, 0→30% ethyl acetate/hexanes)

Sources & evidence

ORD record: ord-624a608e370e41b7998c270bfcc49723
Source dataset: uspto-grants-2011_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08058299B2

Reaction notes

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