Reaction Steps
Method E. Reaction of oxalyl chloride (100 λL, 1.1 mmol) and benzoic acid 4 (207 mg, 0.6 mmol) with subsequent coupling to 3-aminopyridine (58 mg, 0.6 mmol) gave benzamide 5 (148 mg, 59%) as a white powder: mp (EtOAc) 248-250° C.; 1H NMR δ 10.56 (s, 1 H, CONH), 8.94 (d, J=2.2Hz, 1 H, H-2′), 8.33 (dd, J=4.7, 1.5 Hz, 1 H, H-6′), 8.20 (ddd, J=8.3, 2.5, 1.5 Hz, 1 H, H-4′), 8.10 (br d, J=8.6 Hz, 2 H, H-2, H-6), 7.97 (br d, J=8.6 Hz, 2 H, H-3, H-5), 7.69 (br d, J=8.3Hz, 2 H, H-2″, H-6″), 7.38-7.45 (m, 3 H, H-5′, H-3″, H-5″), 4.65 (s, 2 H, CH2SO2), 2.41 (s, 3 H, CH3), 2.16 (s, 3 H, CH3); 13C NMR δ 165.0, 157.9, 150.1, 144.7 (2), 144.5, 142.1, 135.6, 135.5, 129.7 (2), 129.3, 128.6 (2), 128.3 (2), 127.4, 126.1, 125.5 (2), 123.5, 53.0, 21.1, 9.7; MS m/z 448.7 (MH+, 100%). Anal. calcd for C24H21N3O4S: C, 64.41; H, 4.73; N, 9.39. Found: C, 64.18; H, 4.74; N, 9.39%.
