1-Bromo-4-phenylmethoxybenzene → (R)-4-(4-benzyloxyphenyl)-3-methylpiperazine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 1-(benzyloxy)-4-bromobenzene (158 mg, 0.60 mmol), (R)-tert-butyl 3-methylpiperazine-1-carboxylate (60.1 mg, 0.3 mmol), bis(tri-t- butylphosphine)palladium(0) (15.33 mg, 0.03 mmol) and potassium tert-butoxide (37.0 mg, 0.33 mmol) in THF (2 mL) was flushed with nitrogen and sealed into a microwave tube. The reaction was heated to 150 °C for 20 minutes in the microwave reactor and cooled to RT. The reaction mixture was filtered and the filtrate evaporated to dryness. The residue was dissolved in MeOH (5mL) and purified by ion exchange chromatography, using an SCX column. The desired product was eluted from the column using 0.35M NH3/MeOH and pure fractions were evaporated to dryness. The crude product was purified by flash silica chromatography, elution gradient 0 to 20% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford (R)-tert-butyl 4-(4-(benzyloxy)phenyl)-3-methylpiperazine-1-carboxylate (41.0 mg, 35.7 %) as a colourless oil that solidified on standing.

Herkunft & Nachweise