N-ethyl-6-formyl-Imidazo[1,2-a]pyridine-3-carboxamide synthesis

Yield:1004550-12-2 76%

Reaction Conditions:

with 2,6-dimethylpyridine;sodium periodate;osmium(VIII) oxide in 1,4-dioxane;water;tert-butyl alcohol at 20; for 72 h;

Steps:

2.c

6-Ethenyl-Λ/-ethylimidazo[l,2-α]pyridine-3-carboxamide (287 mg, 1.33 mmol), OsO₄ (0.68 mL of a 2.5 wt % solution in t-BuOU, 0.116 mmol), NaIO₄ (1.14 g, 9.24 mmol), 2,6-lutidine (0.31 mL, 4.62 mmol) and 3:1 dioxane/water (12 mL) were combined and stirred at rt. After 72 h, the resultant slurry was diluted with CHCI₃ filtered and the filtrate was washed with water. The aqueous layer was extracted with CHCI₃ (3X) followed by EtOAc (3X) and the combined extracts were dried over Na₂SO₄, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography (1.5 to 3.0% MeOH in CHCI₃) to give 220 mg (76%) of the title compound as a tan solid. MS(ES)+ m/e 218.0 [M+H]⁺.

References:

WO2008/14219,2008,A2 Location in patent:Page/Page column 44