To a suspension of 3-iodo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole-5-carbaldehyde (87 mg, 0.22 mmol), NaOAc (36 mg, 0.44 mmol), nBu4NCl (61 mg, 0.44 mmol), and Pd(OAc)2 (8.0 mg, 0.036 mmol) in DMF (2 mL) under argon was added 4-vinylpyridine (0.05 mL, 0.46 mmol). The resulting mixture was heated in a sealed vial at 100° C. for 14 hours. Ethyl acetate (200 mL) was added and the solution was washed with water (20 mL) and brine (3×20 mL), dried over Na2SO4 and concentrated. The residue was chromatographed (5 g silica SPE tube, Silicycle, 1-2% MeOH in CH2Cl2, repeated for mixed fractions) gave the title compound as a yellow solid (43 mg, 52%). 1H NMR (400 MHz, CDCl3 plus a drop of CD3OD) δ 10.07 (s, 1H), 8.52 (m, 3H), 7.97 (d, J=8.4 Hz, 1H), 7.67 (d, J=8.8 Hz, 1H); 7.60 (d, J=16.4 Hz, 1H); 7.48 (m, 3H); 5.73 (s, 2H), 3.56 (m, 2H), 0.86 (m, 2H), −0.12 (s, 9H).
