Hydrochloric Acid → Tert-butyl 2-[4-(methoxycarbonyl)benzyl]-3-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere, to an N,N-dimethylformamide (2 mL) solution of sodium hydride (60%, 94 mg), an N,N-dimethylformamide (4 mL) solution of tert-butyl 3-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (514 mg) was added at 0° C. The reaction solution was stirred at 50° C. for one hour. The solution was cooled to 0° C. and then an N,N-dimethylformamide (2 mL) solution of methyl 4-(bromomethyl)benzoate (442 mg) was added. The reaction solution was stirred at 0° C. for 30 minutes. To the reaction solution, 0.5N-hydrochloric acid (20 mL) was added. The aqueous layer was extracted twice with ethyl acetate. The aqueous layer was combined with the organic layer, washed in turn with water and saturated brine, and then dried over anhydrous magnesium sulfate. After removing the anhydrous magnesium sulfate by filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (n-hexane:ethyl acetate=1:0→1:2) to obtain the title compound (553 mg) having the following physical properties.

Provenance & Evidence