Lithium Hydroxide → 4-(2-oxopyridin-1(2H)-yl)benzoyl chloride

Participants

Reaction Conditions

Reaction Steps

Part A. To a solution of 4-iodomethylbenzoate is added 2-hydroxypyridine (1 eq), cesium carbonate (1.5 eq) followed by catalytic CuI. The reaction mixture is heated at 100° C. overnight, cooled, and quenched with water. The organics are extracted with ethyl acetate, dried, and evaporated to afford crude product which is purified via silica gel column chromatography (hexane:ethylacetate) to afford the coupled product. Part B. To the product from part A in THF is added LiOH (excess of 1 eq) and water. The reaction mixture is stirred at rt overnight and quenched with dilute HCl. The desired carboxylic acid intermediate is extracted with ethyl acetate, dried, and evaporated to afford the product. Part C. To the product from part B in dichloromethane is added 1 equivalent of thionyl chloride along with cat. DMF. The reaction mixture is stirred at rt overnight and concentrated to afford 4-(2-oxo-pyridin-1-yl)-benzoyl chloride. Part D. To a solution of 2-nitro-5-chloro-benzoylchloride in dichloromethane is added 2-amino-5-chloropyridine (1 eq) and DMAP (excess of 2 eq). The reaction mixture is stirred at rt overnight, quenched with water, and the organics extracted with ethylacetate and dried (magnesium sulfate). Evaporation affords the coupled product. Part E. The product from part A was dissolved in ethyl acetate. To this solution is added 3 equivalents of tin chloride, and the reaction mixture stirred at rt for 4 h. The reaction mixture is quenched with sat'd ammonium hydroxide solution and the organics extracted with ethyl acetate, dried, and evaporated to afford the anilino product. Part F. The product from part B was dissolved in dichloromethane and to this solution is added 4-(2-oxopyridin-1-yl)-benzoyl chloride (1 eq) and DMAP (excess of 2 eq). The reaction mixture is stirred at rt overnight, concentrated, and purified via reverse phase prep. HPLC (acetonitrile/water/TFA) to afford the title compound.

Provenance & Evidence