A solution of 5-fluoro-1-{[2-(3-fluorophenyl)pyrimidine-5-carbonyl]amino}-1H-indole-3-sulfonyl chloride (0.14 g) in DCM (20 mL) is treated with a solution of aqueous ammonia solution (28%-5 mL) in water (15 mL) and stirred at rt for 24 h. The reaction mixture is acidified with 10 N aqueous HCl to pH ˜3 and extracted with DCM. The organic layer is washed with water and brine, dried (MgSO4), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography eluting with 50% EtOAc in heptane to afford 2-(3-fluorophenyl)pyrimidine-5-carboxylic acid-[5-fluoro-3-sulfamoylindol-1-yl)amide (10 mg, 8%) as a solid. MS: 430 (M+H). 1H NMR (300 MHz, DMSO-d6): δ 7.20-7.30 (m, 1H), 7.40-7.50 (m, 2H), 7.60-7.72 (m, 2H), 8.10 (s, 1H), 8.19-8.22 (d, 1H), 8.33-8.37 (d, 1H), 9.44 (s, 1H), 12.45 (s, 1H).
