Reaction Steps
To the solution of 2-methyl-3-{4-phenyl-5-[1-(tetrahydro-2H-pyran-2-yl)-1H-1,2,4-triazol-3-yl]-1,3-thiazol-2-yl}-6-vinylimidazo[1,2-a]pyridine (0.747 g, 1.59 mmol) in Tetrahydrofuran (55 mL, 680 mmol) and Water (16 mL, 890 mmol) was added Sodium metaperiodate (0.852 g, 3.98 mmol), followed by 0.157 M of Osmium tetraoxide in Water (0.53 mL, 0.083 mmol). The solution was stirred at r.t. for 3 days. The mixture was diluted with ˜100 mL of water, filtered to collect the solid product as the first crop of 2-methyl-3-{4-phenyl-5-[1-(tetrahydro-2H-pyran-2-yl)-1H-1,2,4-triazol-3-yl]-1,3-thiazol-2-yl}imidazo[1,2-a]pyridine-6-carbaldehyde (0.255 g, 24% yield). LCMS: (FA) ES+ 471. 1H NMR (400 MHz, d1-chloroform) δ 10.56 (s, 1H), 10.00 (s, 1H), 8.30 (s, 1H), 7.94-7.97 (m, 2H), 7.82-7.85 (m, 1H), 7.69-7.71 (m, 1H), 7.46 (m, 3H), 5.48-5.51 (dd, J=8.78, 2.76 Hz, 1H), 4.06-4.09 (m, 1H), 3.73-3.77 (m, 1H), 2.85 (s, 3H), 2.02-2.15 (m, 3H), 1.59-1.69 (m, 3H). The filtrate was rotavaped to remove THF, extracted with 5% MeOH/DCM (4×60 mL). The combined DCM solution was dried over Na2SO4, filtered, rotavaped to give a crude material. Chromatograph in a 40 g ISCO column using MeOH/DCM (0/100 to 5/95) gave the second crop of 2-methyl-3-{4-phenyl-5-[1-(tetrahydro-2H-pyran-2-yl)-1H-1,2,4-triazol-3-yl]-1,3-thiazol-2-yl}imidazo[1,2-a]pyridine-6-carbaldehyde (fast fraction, 0.104 g, 14% yield), and 1-(2-methyl-3-[4-phenyl-5-[1-(tetrahydro-2H-pyran-2-yl)-1H-1,2,4-triazol-3-yl]-1,3-thiazol-2-yl]imidazo[1,2-a]pyridin-6-yl)ethane-1,2-diol (slow fraction, 0.243 g, 30.3% yield). LCMS: (FA) ES+ 503. 1H NMR (400 MHz, d1-chloroform & d4-methanol) δ 9.90 (s, 1H), 8.28 (s, 1H), 7.86-7.88 (m, 2H), 7.54-7.57 (d, J=9.29 Hz, 1H), 7.37-7.41 (m, 4H), 5.44-5.47 (m, 1H), 4.80-4.82 (m, 1H), 4.02-4.05 (m, 1H), 3.68-3.80 (m, 3H), 2.73 (s, 3H), 2.00-2.11 (m, 3H), 1.65-1.68 (m, 3H).
