Ethyl 6-(1-methylethyl)-4-oxo-1,4-dihydropyridine-3-carboxylate → Ethyl 4-[(3-methoxypropyl)amino]-6-(1-methylethyl)pyridine-3-carboxylate

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Reaction Conditions

Reaction Steps

Ethyl 6-(1-methylethyl)-4-oxo-1,4-dihydropyridine-3-carboxylate (209 mg) was suspended in phosphorus oxychloride (2 ml), and the mixture was stirred at 120° C. for 3 hr. Phosphorus oxychloride was evaporated under reduced pressure, and the mixture was cooled to 0° C. The mixture was neutralized with saturated aqueous sodium hydrogen carbonate and water, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The obtained residue was dissolved in 2-propanol (5 ml), 3-methoxypropylamine (307 μl) and triethylamine (517 μl) were added, and the mixture was stirred with heating to reflux for 15 hr. The reaction mixture was concentrated under reduced pressure, saturated aqueous sodium hydrogen carbonate was added, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The obtained residue was subjected to silica gel chromatography, and the fraction eluted with acetic acid was concentrated under reduced pressure to give the object compound (263 mg).

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