4-Heptanone → 1-{3-[4-(1-Hydroxy-1-propylbutyl)-phenoxy]propyl}piperidine

Beteiligte Stoffe

Reaktionsschritte

To a solution of 4-heptanone (471 mg) in tetrahydrofuran (4 mL) is added a solution of 4-(3-piperidinopropoxy)phenylmagnesium bromide in tetrahydrofuran (11 mL, 3.3 mmol). The mixture is stirred overnight at room temperature and quenched at 0° C. with a saturated aqueous solution of ammonium chloride (20 mL). The solution is extracted with ethyl acetate (20 mL) and the organic layer is washed with a saturated aqueous solution of ammonium chloride (20 mL), dried over magnesium sulphate, concentrated under reduced pressure and purified by chromatography over silica gel with a gradient dichloromethane/methanol from 98/2 to 95/5 as eluent. Fractions containing the expected product are pooled and concentrated under reduced pressure to give 1-{3-[4-(1-hydroxy-1-propylbutyl)-phenoxy]propyl}piperidine as a yellow oil. Salt formation with oxalic acid in ethanol and precipitation with diethyl oxide affords 1-{3-[4-(1-hydroxy-1-propylbutyl)-phenoxy]propyl}piperidine, oxalate as a white solid melting at 118° C.

Herkunft & Nachweise