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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence