3-methoxy-4-[(E)-3-oxo-3-(2-phenylamino-pyridin-3-yl)-propenyl]-benzoic acid methyl ester → 3-Methoxy-4-[3-oxo-3-(2-phenylamino-pyridin-3-yl)-propyl]-benzoic acid methyl ester

Participants

Reaction Steps

A solution of 3-methoxy-4-[(E)-3-oxo-3-(2-phenylamino-pyridin-3-yl)-propenyl]-benzoic acid methyl ester (875 mg, 2.25 mmol) in ethyl acetate was treated with 10% palladium on activated carbon (83 mg). The reaction was stirred under a balloon of hydrogen gas for 6 h. At this time, the reaction was filtered through a pad of Celite®, rinsed with ethyl acetate and concentrated in vacuo. LCMS indicated incomplete conversion to the desired product. Due to solubility issues, the residue was dissolved in acetone (200 mL) at 25° C. and was treated with 10% palladium on activated carbon (83 mg). The reaction was stirred under a balloon of hydrogen gas for 2 d. At this time, the reaction was filtered through a pad of Celite®, rinsed extensively with acetone and concentrated in vacuo. LCMS still indicated incomplete conversion to the desired product. The residue was dissolved in methylene chloride (150 mL) at 25° C. and was treated with 10% palladium on activated carbon (83 mg). The reaction was stirred under a balloon of hydrogen gas for 4 d. At this time, the reaction was filtered through a pad of Celite®, rinsed with methylene chloride (2×50 mL) and concentrated in vacuo. Flash chromatography (40 g silica column, 10-25% ethyl acetate/hexanes) afforded 3-methoxy-4-[3-oxo-3-(2-phenylamino-pyridin-3-yl)-propyl]-benzoic acid methyl ester (313.4 mg, 35.6%) as a yellow solid.

Provenance & Evidence