A microwave vial was charged with 3-bromo-N-(2,4-dimethoxybenzyl)-1-methyl-N-(1,2,4-thiadiazol-5-yl)-1H-indole-6-sulfonamide (Intermediate D) (48.17 mg, 0.092 mmol), (2-(1-methyl-1H-pyrazol-5-yl)-4-(trifluoromethyl)phenyl)boronic acid (Intermediate G) (32.3 mg, 0.120 mmol), potassium phosphate (58.6 mg, 0.276 mmol), and Pd(AmPhos)2Cl2 (3.26 mg, 4.60 μmol). The vial was flushed with Ar, then 1,4-dioxane (0.4 mL) and water (0.125 mL) were added in sequence. The vial was sealed and heated in a microwave reactor at 90° C. for 20 min. The mixture was diluted with water, then extracted with EtOAc (3×). The combined organic extracts were concentrated. The residue was taken up in MeOH (1 mL), and cooled in an ice bath for 5 min. Acetyl chloride (65.4 μl, 0.920 mmol) was added dropwise, and the resulting mixture was stirred for 2 h. The mixture was concentrated under vacuum to remove excess HCl, and the residue was taken up in 2N ammonia in methanol. The resulting mixture was again concentrated under vacuum. The crude product was purified by chromatography on silica gel (0 to 10% MeOH/DCM) to give 1-methyl-3-(2-(1-methyl-1H-pyrazol-5-yl)-4-(trifluoromethyl)phenyl)-N-(1,2,4-thiadiazol-5-yl)-1H-indole-6-sulfonamide (35.38 mg, 0.068 mmol, 74.1% yield) as a light-yellow solid. 1H NMR (400 MHz, DMSO-d6) δ=8.37 (s, 1 H), 7.97-7.83 (m, 3 H), 7.77 (d, J=1.9 Hz, 1 H), 7.60-7.53 (m, 1 H), 7.47-7.36 (m, 2 H), 7.17 (s, 1 H), 6.35 (d, J=1.9 Hz, 1 H), 3.81 (s, 3 H), 3.22 (s, 3 H). m/z (ESI) 519.2 (M+H)+.
