To a 50 mL round bottom flask were added commercially available 4-(3-amino-1H-indazol-5-yl)-6-(2-isobutoxyphenyl)pyrimidin-2(1H)-one (130 mg, 0.35 mmol), m-anisaldehyde (420 μL, 3.5 mmol, 10 eq), dimethylformamide (10 mL) and glacial acetic acid (10 drops). The reaction mixture was heated to 50° C. in an oil bath and stirred for 1 h. The mixture was allowed to cool before adding sodium cyanoborohydride (1M THF solution (Aldrich), 3 mL, 3 mmol) and subsequently stirred at room temperature for 1 h. Formation of product was confirmed by LC/MS and was purified by preparatory HPLC (reverse-phase, acetonitrile/water with 0.1% formic acid) to yield 40 mg (98%) of the title compound: 1H-NMR (400 MHz, d6-DMSO): δ 11.78 (s, 1H), 11.64 (s, 1H), 8.73 (s, 1H), 8.06 (d, 1H), 7.60 (d, 1H), 7.46-7.54 (m, 1H), 7.28-7.34 (m, 1H), 7.15-7.26 (m, 2H), 7.06-7.12 (m, 1H), 6.96-7.01 (m, 1H), 6.73-6.81 (m, 1H), 4.42-4.48 (m, 2H), 3.82-3.88 (m, 2H), 3.72 (s, 3H), 1.94-2.07 (m, 1H), 0.90-0.95 (m, 6H). MS (EI) for C29H29N5O3: 495 (MH+).
