Benzothiazole → [2-Benzothiazolyl][1-[2-(4-methoxyphenyl)ethyl]-4-piperidinyl)methanone

Participants

Reaction Conditions

Reaction Steps

Dissolve freshly distilled benzothiazole (3.41 g, 25.24 mmol) in anhydrous tetrahydrofuran (60 mL), place under an argon atmosphere and cool to -78° C. Add, by dropwise addition, n-butyllithium (15.14 mL of a 2.5M solution in hexane, 37.86 mmol) and stir briefly at -78° C. Add, by dropwise addition, a solution of 1-[2-(4-methoxyphenyl)ethyl]-4-piperidinecarboxylic acid, methyl ester (7.0 g, 25.24 mmol) in anhydrous tetrahydrofuran (40 mL). Stir for 1 hour at -78° C., quench with methanol (5 mL) and pour into saturated ammonium chloride (100 mL). Filter, separate the organic phase and extract the aqueous phase with ethyl acetate. Combine the organic phases and wash with water and brine. Dry (MgSO4) and evaporate the solvent in vacuo. Purify by chromatography (ethyl acetate) and recrystallize (cyclohexane) to give the title compound as a pale yellow powder; mp 118°-120° C.

Provenance & Evidence