Sodium Acetate → HCID 178470000, Verbindung

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

4-Hydrazino-cyclohexanol, hydrochloride (0.255 g, 1.53 mmol, prepared in Example 67, Step 2), 2-dimethylaminomethylene-4,4,4-trifluoro-3-oxo-butyric acid ethyl ester (0.272 g, 1.14 mmol) and anhydrous sodium acetate (0.256 g, 3.12 mmol) were combined in ethanol (2.0 mL) and heated at 70° C. under argon for 14 hours. After cooling to room temperature, the reaction mixture was partitioned between methylene chloride and water. The aqueous phase was washed a second time with methylene chloride. The two organic phases were combined, washed with brine, dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography (eluting with a 40-100% ethyl acetate-hexanes gradient) successfully separated the cis-trans isomers, yielding cis-1-(4-hydroxy-cyclohexyl)-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (96.1 mg, 27%) and trans-1-(4-hydroxy-cyclohexyl)-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (63.5 mg, 18%).

Herkunft & Nachweise