Hydrochloric Acid → 2-(Trimethylsilyl)ethyl 4-[2-azido-1-(4-bromophenyl)ethyl]piperidinecarboxylate

Participants

Reaction Steps

Preparation 1-B: A solution of hydrogen chloride in 1,4-dioxane (4 M, 60 mL, 240 mmol) was added to tert-butyl 4-[2-azido-1-(4-bromophenyl)ethyl]piperidinecarboxylate 13 (2.5 g, 6.1 mmol). The reaction mixture was stirred at room temperature for 1 h. The solvent was evaporated under reduced pressure. The residue containing 4-[2-azido-1-(4-bromophenyl)ethyl]piperidine hydrochloride 14 was dissolved in a 50% v/v aqueous tetrahydrofuran solution (68 mL). Potassium carbonate (2.12 g, 15.3 mmol) and 2-(trimethylsilyl)ethyl p-nitrophenyl carbonate (1.74 g, 61.4 mmol) were added. The reaction mixture was stirred at room temperature for 3 h. Organic solvent was evaporated under reduced pressure. Ethyl acetate was added. The organic layer was washed with aqueous sodium bicarbonate solution, water and brine. The organic layer was dried over sodium sulfate. The solvent was evaporated under reduced pressure. The crude product was purified by flash column chromatography eluted with ethyl acetate-hexanes (1:5 v/v) to afford 2-(trimethylsilyl)ethyl 4-[2-azido-1-(4-bromophenyl)ethyl]piperidinecarboxylate 15 (2.1 g, 4.6 mmol). MS (LCMS-Electrospray) 454.1 MH+.

Provenance & Evidence