Triethylamine → tert-Butyl (2R)-2-[(4-benzylpiperazin-1-yl)carbonyl]piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

1-Benzylpiperazine (2.7 ml) and (2R)-1-BOC-piperazine-2-carboxylic acid (3.571 g) were suspended in DMF (150 ml) and stirred at 0° C. Triethylamine (4.33 ml) was added followed by PyBOP reagent (8.08 g). The mixture was allowed to warm to room temperature overnight, concentrated to approximately a third of the volume in vacuo and partitioned between brine (75 ml) and ethyl acetate (2×200 ml). Combined organic extracts were treated with saturated aqueous sodium bicarbonate (75 ml) and brine (75 ml), dried (sodium sulphate), concentrated in vacuo using high vacuum to remove DMF traces and purified by chromatography eluting with 0-15% methanol/dichloromethane. This gave tert-butyl (2R)-2-[(4-benzylpiperazin-1-yl)carbonyl]piperazine-1-carboxylate as a white glass (5.01 g).

Provenance & Evidence