8-fluoroquinoline-4-carbaldehyde synthesis

Yield:-

Reaction Conditions:

with selenium(IV) oxide in 1,4-dioxane;water; for 2.5 h;Heating / reflux;

Steps:

16.b 8-Fluoro-4-quinolinecarboxaldehyde

To a solution of the product of part a) (8.25 g) in dioxane (20 ml) at 70C was added, dropwise over 20 min. , a solution of selenium dioxide in dioxane (15 ml) and water (5 ml). The reaction mixture was refluxed for 2.5 hrs. and then ambient temperature for 20 hrs. To the resulting mixture was added ethyl acetate and the suspension was decanted from the solid selenium metal. The organic layer was then evaporated under reduced pressure and the residue was purified by column chromatography over silica, eluting with DCM/diethyl ether (1 : 1) to give the sub-title compound as a solid (3.61 g). MS (ESI) 176 [M+H] + IHCSCI3 7. 54 (1H, M), 7.67 (1H, M), 7.83 (1H, D), 8.82 (1H, d), 9. 26 (1H, d), 10. 52 (1H, s)

References:

WO2004/65394,2004,A1 Location in patent:Page 46