Reaction #2320112

Reaction equation

5-Bromo-2-chlorobenzotrifluoride

1-benzyl-4-piperidone

→

title compound

Yield 64.0%

1-Benzyl-4-(4-chloro-3-trifluoromethyl-phenyl)-piperidine-4-ol

Yield 64.0%

Solvents

diethyl ether

diethyl ether

diethyl ether

Conditions

Workup

1. 1
   OtherThe reaction gave rise to a solution of Grignard's reagent
2. 2
   Otherfinally quenched with saturated ammonium chloride solution (40 ml)
3. 3
   ExtractionThe mixture was extracted several times with EtOAc
4. 4
   Dryingthe combined organic phases were dried (MgSO4)
5. 5
   Filtrationfiltered
6. 6
   Otherevaporated to dryness

Procedure

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).

Source