Reaction Steps
A solution of 1,1′-carbonyldiimidazole (86.2 mg, 0.531 mmol), 2-aminobenzothiazole (72.6 mg, 0.483 mmol), and DIPEA (0.17 mL, 0.97 mmol) in CH2Cl2 (5 mL) and DMF (3 mL) was stirred at room temperature for 4 h. The mixture was concentrated to a minimum volume, diluted with DMF (3 mL), and COMPOUND 249 (150 mg, 0.482 mmol) was added and stirred at 60° C. for 16 hours. The solution was concentrated to dryness, treated with saturated aqueous NaHCO3 (30 mL) and H2O (10 mL), and extracted with CH2Cl2 (3×15 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated. Purification of the crude material by flash chromatography on silica gel (CH2Cl2/MeOH/NH4OH, 90:5:5) provided COMPOUND 291 (107 mg, 45%) as a white solid. 1H NMR (CDCl3) δ 1.57-1.76 (m, 2H), 1.94 (d, 2H, J=11.7 Hz), 2.05 (s, 6H), 2.62-2.84 (m, 3H), 3.79 (s, 4H), 4.26 (d, 2H, J=11.7 Hz), 7.02-7.11 (m, 2H), 7.16-7.27 (m, 1H), 7.29-7.40 (m, 3H), 7.58 (d, 1H, J=7.8 Hz), 7.74 (d, 1H, J=7.5 Hz), 8.33 (d, 2H, J=3.9 Hz), 9.91 (br s, 1H); 13C NMR (CDCl3) 18.36, 27.44, 44.89, 54.89, 57.59, 119.09, 121.83, 122.84, 123.55, 126.34, 131.83, 133.77, 138.46, 146.27, 147.01, 154.75, 157.37, 163.38; ES-MS m/z 509 (M+Na). Anal. Calcd. for C27H30N6OS.1.0 CH2Cl2: C, 58.84; H, 5.64; N, 14.70. Found: C, 58.69; H, 5.57; N, 14.82.
