To a solution of 1-(benzo[d][1,3]dioxol-5-yl)-N-(2-tert-butyl-6-fluoroindolin-5-yl)cyclopropanecarboxamide (340 mg, 0.86 mmol) in anhydrous MeOH (5.7 mL) containing 1% of acetic acid was added glyoxal 40% in water (0.60 mL, 5.2 mmol) at room temperature under N2. After 20 min of stirring, NaBH3CN (120 mg, 1.9 mmol) was added in one portion and the reaction mixture was stirred overnight at room temperature. The solvent was removed under reduced pressure and the residue obtained was purified by column chromatography on silica gel (10-40% ethyl acetate/hexanes) providing a pale yellow oil which was treated with 50/50 CH3CN—H2O containing 0.05% TFA and CDCl3. Solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (20-35% ethyl acetate/hexanes) to give 1-(benzo[d][1,3]dioxol-5-yl)-N-(2-tert-butyl-6-fluoro-1-(2-hydroxyethyl)-1H-indol-5-yl)cyclopropanecarboxamide. 1H NMR (400 MHz, CDCl3) δ 8.02 (d, J=7.7 Hz, 1H), 7.30 (d, J=2.1 Hz, 1H), 6.93 (dd, J=1.6, 7.9 Hz, 1H), 6.90 (d, J=1.6 Hz, 1H), 6.90 (d, J=1.6 Hz, 1H), 6.78 (d, J=7.9 Hz, 1H), 6.08 (s, 1H), 5.92 (s, 2H), 4.21 (dd, J=6.9, 6.9 Hz, 2H), 3.68 (m, 2H), 2.28 (s, 1H), 1.60 (dd, J=3.7, 6.7 Hz, 2H), 1.35-1.32 (m, 9H), 1.04 (dd, J=3.7, 6.8 Hz, 2H). MS (ESI) m/e (M+H+) 439.0.
