Water → Tert-butyl 4-(2-chloroacetyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To an ice-cold solution of chloroacetyl chloride (1.27 g, 10 mmol) in 15 mL of methylene chloride was added N-tert-butoxycarbonylpiperazine (1.27 g, 11 mmol) in 10 mL of methylene chloride containing triethylamine (2.17 g, 20 mmol). The reaction mixture was stirred at 5° C. for 30 minutes, then warmed to room temperature and stirred for 24 hours. Water (20 mL) was added at 5° C., and the reaction mixture was diluted with methylene chloride (200 mL). The organic layer was separated, washed with saturated aqueous NaHCO3 (2×100 mL), brine (2×100 mL), dried over MgSO4, filtered, and concentrated at reduced pressure. The concentrated residue was purified by flash column chromatography on silica gel eluting with ethyl acetate to give 2.20 g (84.0%) of 1-(2-chloroacetyl)-4-(tert-butoxycarbonyl)piperazine as a yellow liquid. 1H NMR (300 MHz / CDCl3): δ 1.46 (s, 9H), 3.41-3.60 (m, 8H), 4.07 (s, 2H). HRMS: calcd for C11H19NO3 Cl1 262.1084, found 262.1079.

Provenance & Evidence