Reaction Steps
A mixture of fluoride 48 (112 mg, 0.24 mmol) and 1-methylpiperazine (1 mL) in DMSO (1 mL) was stirred in a sealed tube at 130° C. for 16 h. The solvent was evaporated and the residue was suspended in ice/water (50 mL) for 1 h. The mixture was partitioned between CHCl3 (200 mL) and water (50 mL) and the solvent evaporated. The mixture was dissolved in EtOAc (5 mL) and the precipitated filtered to give benzamide 49 (41 mg, 31%) as a white powder: mp (EtOAc) 210-215° C.; 1H NMR δ 9.23 (s, 1H, CONH), 8.56 (br s, 1H, H-2′), 8.46 (dd, J=4.8, 1.6 Hz, 1H, H-6′), 8.00 (d, J=8.6 Hz, 2H, H-2, H-6), 7.91 (d, J=8.6 Hz, 2H, H-3, H-5), 7.73 (dt, J=8.0, 2.0 Hz, 1H, H-4′), 7.50 (d, J=9.1 Hz, 2H, H-3″, H-5″), 7.36 (ddd, J=7.9, 4.7, 0.6 Hz, 1H, H-5′), 7.02 (d, J=9.1 Hz, 2H, H-2″, H-6″), 4.49-4.53 (m, 4H, CH2SO2, CH2N), 3.30 (br t, J=4.9 Hz, 4H, 2×CH2N), 2.40 (br t, J=4.9 Hz, 4H, 2×CH2N), 2.20 (s, 3H, CH3), 2.12 (s, 3H, CH3); 13C NMR δ 165.5, 157.8, 154.0, 149.6, 148.8, 148.1, 135.3, 135.1, 134.9, 129.7 (2), 128.8, 128.0 (2), 126.4, 125.4 (2), 123.4 (2), 113.3 (2), 54.1 (2), 53.2, 46.4 (2), 45.6, 40.4, 9.6; MS m/z 546.8 (MH+, 100%).
