Cesium carbonate → Tert-butyl 4-(4-(2-methoxy-2-oxoethyl)phenyl)piperazine-1-carboxylate

Participants

Reaction Steps

A flask charged with cesium carbonate (4.6 g, 14.0 mmol), palladium (II) acetate (0.07 g, 0.3 mmol), and (S)-BINAP (0.28 g, 4.5 mmol) was evacuated and flushed with dry nitrogen. Methyl 2-{4-[(trifluoromethyl)sulfonyloxy]phenyl}acetate (3.0 g, 10.0 mmol) and t-butyl-1-piperazinecarboxylate (2.3 g, 12.0 mmol) in 20 mL toluene was added via syringe and the resultant mixture was stirred at ambient temperature for 30 minutes and at 80° C. for 16 hours. The reaction mixture was removed from the heating bath, concentrated, and chromatographed on silica gel (0 to 30% ethyl acetate/hexane) providing 1.7 g (50%) of the title compound. 1H NMR (300 MHz, CDCl3) δ7.20 (d, J=8.5 Hz, 2H), 6.89 (d, J=8.4 Hz, 2H), 3.70 (s, 3H), 3.59 (t, J=5.0 Hz, 4H), 3.57 (s, 2H), 3.12 (t, J=5.2 Hz, 4H), 1.50 (s, 9H); ESI (M+H)+=335.

Provenance & Evidence