1-Benzyl-4-piperidone → 1-Benzyl-4-[4-chloro-3-(trifluoromethyl)phenyl]-4-piperidinol

Participants

Reaction Steps

A solution of 5-Bromo-2-chlorobenzotrifluoride (5 g, 19.2 mmol) in dry diethyl ether (40 ml) was added dropwise at room temperature to a mixture of Mg (470 mg) in dry diethyl ether (20 ml) under a stream of Argon (g). The reaction gave rise to a solution of Grignard's reagent. A solution of 1-benzyl-4-piperidone (1.3 g, 6.88 mmol) in dry diethyl ether (30 ml) was added dropwise via syringe at room temperature. The combined mixture was stirred for 1 hour, and finally quenched with saturated ammonium chloride solution (40 ml). The mixture was extracted several times with EtOAc and the combined organic phases were dried (MgSO4), filtered and evaporated to dryness. The oily residue was chromathographed on a silica column using EtOAc:toluene (1:1 (v/v)) as eluent affording the title compound (1.6 g, 64%). MS m/z (relative intensity, 70 eV) 369 (M+, 23), 278 (15), 91 (bp), 65 (16), 56 (21).

Provenance & Evidence