Hydrochloric Acid → Cyclopentyl 4-trifluoromethylphenyl ketone

Beteiligte Stoffe

Reaktionsschritte

To a cold (0° C.) solution of N-methoxy-N-methyl-4-(trifluoromethyl)benzamide (3.44 g, 14.75 mmol) in anhydrous THF (70 mL) was added dropwise over a period of 30 minutes a solution of cyclopentylmagnesium bromide (2 M in diethyl ether, 29.5 mmol, 14.75 mL) under inert atmosphere of N2. The reaction mixture was slowly allowed to warm to rt overnight. An aqueous solution of HCl (1N, 50 mL) was added and the resulting mixture was extracted with diethyl ether (3×50 mL). The combined organic layers were washed with brine (1×50 mL), dried over MgSO4, filtered and evaporated under vacuum to give a brown oil (3.0 g). Purification by chromatography (SiO2, DCM/c-Hex 1/3) gave the title compound as a colorless oil (610 mg, 17%). 1H NMR (CDCl3, 300 MHz) δ 8.24 (d, J=8.1 Hz, 2H), 7.90 (d, J=8.1 Hz, 2H), 3.96-3.79 (m, 1H), 2.21-2.00 (m, 4H), 2.01-1.71 (m, 4H). HPLC (Condition A), Rt: 5.22 min (HPLC purity: 98.6%).

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