1-Methylpiperazine → 1-{2,2-Dimethyl-3-[4-(4-methylphenyl)-piperazin-1-yl]-3-oxopropyl}-4-methylpiperazine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

3-Bromo-1-(4-methylphenyl)piperazine-2,2-dimethylpropan-1-one (6.00 g, 17.68 mmol) was dissolved in N-methylpyrrolidinone (12 mL). N-Methylpiperazine (4.12 mL, 37.94 mmol) was added. The reaction mixture was split into four batches and each was heated at 200° C. for 15 minutes in a Biotage Initiator microwave at high absorption. The reaction mixtures were combined and dissolved in DCM (300 mL), and washed with a 0.5M aq KOH solution (100 mL), water (100 mL), brine (100 mL), and then dried (MgSO4) and concentrated in vacuo. The residue was dissolved in DCM (100 mL) and methyl isocyanate resin (2.0 g) was added, and the reaction mixture was shaken for 48 hours, filtered and then concentrated in vacuo. The resulting residue was purified by reverse phase chromatography (gradient eluting with MeOH in water, with 1% formic acid in each solvent, 0-30%). The resulting residue was dissolved in DCM (100 mL) and stirred with solid K2CO3 for 20 minutes, filtered and concentrated in vacuo, to give a pale brown oil which was recrystallised from heptane to give 1-{2,2-dimethyl-3-[4-(4-methylphenyl)-piperazin-1-yl]-3-oxopropyl}-4-methylpiperazine (1.47 g, 23.2%) as a white solid.

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