(Diethylamino)sulfur trifluoride → 4-(4-Bromophenyl)-4-fluoro-1-methylpiperidine

Participants

Reaction Steps

To a solution of DAST (0.50 g, 3.8 mmol) in CH2Cl2 was added a solution of 4-(4-bromophenyl)-1-methylpiperidin-4-ol (0.507 g, 1.88 mmol) in CH2Cl2 at −78° C. The resulting mixture was warmed to rt over a period of 3 h. The reaction was then allowed to cool to 0° C. and quenched with saturated NaHCO3. The resulting mixture was extracted with CH2Cl2 and the combined organic extracts were dried over MgSO4 and concentrated to give a yellow oil. The crude product was purified by silica gel chromatography (95:5 EtOAc/NH3 to 10:8:2 CH2Cl2/MeOH/NH3) to yield an inseparable mixture of the title compound and 4-(4-bromophenyl)-1-methyl-1,2,3,6-tetrahydropyridine (280 mg, used without further purification).

Provenance & Evidence