1-[(4-fluorophenyl)methyl]-1H-1,3-benzodiazole → [1-[2-(4-Methoxyphenyl)ethyl]-4-piperidinyl]methanone

Beteiligte Stoffe

Reaktionsschritte

To a stirred, -78° C., solution of 1-[(4-fluorophenyl)methyl]-1H-benzimidazole (1.13 g, 5.00×10-3 mole) and dry THF (12 ml) under argon was added a 2.5 molar hexane solution of n-butyl lithium (2.1 ml, 5.25×10-3 mole). After 15-20 minutes at -78° C., a solution of 1-[2-(4-methoxyphenyl)ethyl]-4-piperidinecarboxylic acid, methyl ester (1.39 g, 5.01×10-3 mole) and dry THF (6 ml) was added dropwise via syringe. After 5-10 minutes, the cooling bath was removed and the reaction was allowed to warm. After ca. 30 minutes, the reaction was quenched by the addition of saturated aqueous NH4Cl. The reaction was transferred to a separatory funnel where the aqueous mixture was extracted two times with ethyl acetate. The ethyl acetate extracts were combined, washed with saturated aqueous NaCl, and dried over anhydrous Na2SO4. The drying agent was removed by filtration and the filtrate was evaporated at reduced pressure affording a viscous oil. This was purified by a combination of flash chromatography (ethyl acetate) and crystallization (cyclohexane) affording 1-[(4-fluorophenyl)methyl]-1H-benzimidazol-2-yl][1-[2-(4methoxyphenyl)ethyl]-4-piperidinyl]methanone as off white matted needles: 0.90 g (38%), m.p. 109-111° C.

Herkunft & Nachweise