Hydrochloric Acid → (+)-4-[(4-Fluorophenoxy)phenyl]methyl-piperidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The alcohol prepared above (1.3 g, 4.5 mmol) dissolved in DMSO (10 mL) was added over an NaH (60%, 210 g) suspension in DMSO (5 mL). Potassium benzoate (715 g, 4.5 mmol) and 1,4-difluorobenzene (0.75 mL, 6.86 mmol) were added and the mixture heated (70-75° C.) until the starting substance disappeared. The reaction mixture was poured into water and saturated aqueous NaCl solution, and extracted with ether. The oil obtained was refluxed with a mixture of methanol (17 mL) and an aqueous hydrochloric acid (17 mL) solution for 1 h. The usual working of the reaction provided (−)-4-[(4-fluorophenoxy)phenyl]methyl-piperidine as an oil in a 64% yield. Treatment of this oil with L-dibenzoyltartaric acid in ethanol (96%, 35 mL) provided a precipitate which was filtered (m.p.=193-194° C.). The aminoether was released yielding a white solid with a 98% ee, m.p.=100-102° C., and [α]546−14, c=0.2, CHCl3).

Herkunft & Nachweise