Hydrochloric Acid → N-Ethyl-4-hydroxy-4-(3-(1-methylethoxy)phenyl)piperidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of 1-bromo-3-(1-methylethoxy)benzene (5.0 g, 23 mmol) in anhydrous tetrahydrofuran (50 ml) at −78° C. under an atmosphere of nitrogen was added n-butyllithium (1.6M in hexane, 13.7 ml, 22 mmol) dropwise. The reaction mixture was stirred for 1 h at −78° C., before N-ethyl-4-piperidone (2.95 ml, 22 mmol) was added dropwise at −78° C. over 15 minutes, and the reaction mixture was then warmed to −20° C. over 30 minutes. The solution was poured onto 2N aqueous hydrochloric acid (35 ml) and this was further acidified to pH 1 with concentrated hydrochloric acid. Hexane (50 ml) was added and the two layers were separated. The organic layer was discarded and the pH of the aqueous layer was adjusted to 14 using sodium hydroxide pellets. The basic aqueous layer was extracted with hexane:diethyl ether (1:1, 5×50 ml) and the combined extracts were dried (MgSO4) and concentrated to give the title compound as a crude oil (4.2 g, 73% crude yield) which was used without further purification.

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