Bromide ion → tert-Butyl piperazine-1-carboxylate

Part B: To a solution of the bromophenyl ether of Part A (10.0 g, 41.1 mmol) in toluene (80 mL) was added 1-tert-butylcarbonylpiperazine (Lancaster, 9.2 g, 49.4 mmol) and sodium tert-butoxide (Fluka, 5.5 g, 57.5 mmol). The reaction stirred at ambient temperature for twenty min. BINAP (Aldrich, 0.8 g, 1.2 mmol) and tris(dibenzylideacetone)dipalladium (0) (Aldrich, 0.4 g, 0.4 mmol) were then added and the reaction was stirred at 80° C. until the bromide was exhausted. Work up comprised cooling the mixture to ambient temperature, filtering through a Celite® pad, and concentrating the filtrate. The resulting residue was purified on silica gel (ethyl acetate/hexanes) to afford the BOC-piperazine as a black oil (6.4 g, 44% yield). 1H NMR showed the desired compound.

1. temperatureWork up comprised cooling the mixture to ambient temperature
2. filtrationfiltering through a Celite® pad
3. concentrationconcentrating the filtrate
4. customThe resulting residue was purified on silica gel (ethyl acetate/hexanes)

ORD-Eintrag

ord-67ce7503580c432dae09953a015320cc

Quelldatensatz

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06372758B1