1-(tert-Butoxycarbonyl)-4-piperidinecarboxylic acid → 1-Tert-butyl 4-chloromethyl piperidine-1,4-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a mixture of 1-(tert-butoxycarbonyl)piperidine-4-carboxylic acid (3 g, 13.1 mmol) in dichloromethane (40 mL) and water (50 mL) was added NaHCO3 (4.4 g, 52.3 mmol) and tetrabutylammonium hydrogen sulfate (444 mg, 1.3 mmol). After stirring the mixture in an ice bath at 0° C. for ˜10 min, chloromethyl chlorosulfate (2.59 g, 15.7 mmol) in 10 mL of dichloromethane was added dropwise. The reaction mixture was allowed to warm up to rt and stirred vigorously overnight. The mixture was transferred to a separatory funnel with dichloromethane and water (200 mL, each). The organic layer was washed with additional water and brine, dried (Na2SO4), and concentrated in vacuo to give 1-tert-butyl 4-chloromethyl piperidine-1,4-dicarboxylate as a clear oil (3.5 g, 96% yield). This material was used without further purification. 1H NMR (DMSO-d6) δ 1.26-1.48 (m, 11H, CHH, CHH, tertBu), 1.83 (dd, J=3.0, 13.2 Hz, 2H, CHH, CHH), 2.58-2.75 (m, 1H, CH), 2.74-2.99 (m, 2H, CHH, CHH), 3.61-4.02 (m, 2H, CHH, CHH), 5.87 (s, 2H, CH2O); 13C NMR (DMSO-d6) δ 27.16, 27.98, 39.58, 42.35, 69.41, 78.67, 153.75, 172.25; LCMS: MH=278.

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