Cyclobutanone → tert-butyl (2R)-2-[(4-benzylpiperazin-1-yl)carbonyl]-4-cyclobutylpiperazine-1-carboxylate

Participants

Reaction Steps

tert-Butyl (2R)-2-[(4-benzylpiperazin-1-yl)carbonyl]piperazine-1-carboxylate (4.5 g) was dissolved in tetrahydrofuran (300 ml) and stirred at room temperature. N,N-Diisopropyl-ethylamine (5.95 ml) was added followed by cyclobutanone (3.25 g) and magnesium sulphate (300 mg). After 45 minutes, sodium triacetoxyborohydride (9.78 g) was added and stirring continued overnight. Inorganic residues were removed by filtration and the filtrate concentrated in vacuo. The residue was purified by chromatography eluting with 0-10% methanol/dichloromethane. This gave tert-butyl (2R)-2-[(4-benzylpiperazin-1-yl)carbonyl]-4-cyclobutylpiperazine-1-carboxylate as a colourless gum (5.12 g).

Provenance & Evidence