Potassium Carbonate → 2'-(Benzyloxy)-2-[4-(tert-butoxycarbonyl)piperazin-1-yl]-4'-fluoroacetophenone

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Reaktionsschritte

1-(tert-Butoxycarbonyl)piperazine (808 mg, 4.34 mmol) was added to a mixture of 2′-(benzyloxy)-2-bromo4′-fluoroacetophenone (assumed 4.13 mmol) and potassium carbonate (856 mg, 6.20 mmol) in DMF, and stirred for 18 h at room temperature. The solvent was removed in vacuo, the residue taken up in ethyl acetate (150 mL) and washed with water (100 mL) and brine (100 mL). The organice layer was dried (MgSO4) and the solvents removed in vacuo. The crude product was purified by flash chromatography, eluting with 9:1 hexane:EtOAc followed by 1:1 hexane:EtOAc to give pure 2′-(benzyloxy)-2-[4-(tert-butoxycarbonyl)piperazin-1-yl]-4′-fluoroacetophenone (1.42 g, 80% over 2 steps) as a yellow oil; Rf 0.00 (9:1 hexane:EtOAc), 0.50 (1:1 hexane:EtOAc); δH (CDCl3) 7.89 (1H, dd, J=9.3 and 6.9 Hz), 7.48-7.44 (5H, m), 6.81-6.77 (2H, m), 5.17 (2H, s), 3.79 (2H, s), 3.51-3.47 (4H, m), 2.44-2.41 (4H, m), 1.50 (9H, s); LCMS retention time 2.10 min, M+H+ 429.4.

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