N-(2-(2-Amino-6-chlorobenzoyl)-5-chloro-pyridin-3-yl)-4-chloro-3-(trifluoromethyl)benzenesulfonamide (26 mg, 0.05 mmol) in THF (2 mL) was treated with TMS-isocyanate (100 mg) and AcOH (0.5 mL) and then stirred at 75° C. for 12 h. To the mixture was added MeOH (0.5 mL), followed by NaOH (5 N, 1 mL), and the resultant mixture stirred at 75° C. for another 2 h. To the mixture was added AcOH (0.5 mL), and the mixture was purified through HPLC and dried (lyophilizer) to afford the title compound: 1H NMR (400 MHz, CDCl3) δ 8.82 (s, 2H), 8.34 (d, 1H), 8.14 (d, 1H), 7.90 (dd, 1H), 7.66 (d, 1H), 7.46 (s, 1H), 7.16 (t, 1H), 6.90 (d, 2H), 6.81 (d, 1H), 6.14 (d, 1H); MS (ES) (M+H)+ expected 550.9. found 550.9.
