Cesium carbonate → 4-Cyclopropyl-2-fluoro-1-nitrobenzene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A stirred suspension of trifluoro-methanesulfonic acid 3-fluoro-4-nitro-phenyl ester (5.6 g, 19 mmol), cyclopropyl boronic acid (2.09 g, 23.3 mmol) Pd(dppf)Cl2 (1.24 g, 1.5 mmol) and 2M aqueous cesium carbonate (30 mL, 60 mmol) in toluene (20 mL) was degassed before being heated at 90° C. under an argon atmosphere for 2.5 hours. The reaction mixture was allowed to cool to room temperature before filtering through a pad of Celite®, washing with ethyl acetate. The filtrate was washed (water, brine), and then dried (MgSO4), filtered and concentrated in vacuo. The resultant residue was subjected to flash chromatography (Si—PPC, gradient 0-30% ethyl acetate in pentane) to give the title compound as a yellow solid (2.79 g, 81%). 1H NMR (DMSO-d6, 400 MHz) 8.03 (1 H, t, J=8.39 Hz), 7.28 (1 H, dd, J=13.19, 1.91 Hz), 7.16 (1 H, dd, J=8.61, 1.90 Hz), 2.14-2.05 (1 H, m), 1.21-1.05 (2 H, m), 0.92-0.82 (2 H, m).

Herkunft & Nachweise