Triethylamine → 1-(tert-Butoxycarbonyl)-4-(methanesulfonyloxy)piperidine

Participants

Reaction Steps

To an ice-cooled solution of tert-butyl-4-hydroxypiperidine-1-carboxylate (50, 2.20 g, 10.93 mmol) and Et3N (7.5 mL, 54.65 mmol) in CH2Cl2 (25 mL) was added a solution of mesyl chloride (1.5 g, 13.12 mmol) in CH2Cl2 (5 mL). The mixture stirred at room temperature for 3 h then washed with saturated aqueous NaHCO3 (3×5 mL) solution. The organic layer was washed with water (10 mL), brine (10 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to give tert-butyl-4-(methylsulfonyloxy)piperidine-1-carboxylate as a colorless syrup (3.30 g). The residue was dissolved in anhydrous DMF (25 mL) followed by addition of KSAc (2.77 g, 24.3 mmol). The mixture was heated at 60° C. for 16 h then cooled to room temperature and poured over ice-water (225 mL). The aqueous mixture was extracted with Et2O (3×25 mL). The organic layer was washed with H2O (10 mL), brine (10 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to give tert-butyl-4-(acetylthio)piperidine-1-carboxylate as a white solid (51, 1.5 g, 48% over two steps); 1H NMR (300 MHz, CDCl3): δ 3.91 (m, 1H), 3.08-2.94 (m, 2H), 1.89-1.78 (m, 2H), 1.59 (s, 3H), 1.54-1.39 (m, 4H), 1.46 (s, 9H).

Provenance & Evidence