Ethyl Acetoacetate → Ethyl 2-(1-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yl)-3-oxobutanoate

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Reaction Steps

To a stirred solution of ethyl 3-oxobutanoate (2.5 g, 19 mmol) in tetrahydrofuran (50 mL) was added sodium hydride (60% w/w, 0.96 g, 23.9 mmol) in batches at 0° C. The mixture was stirred at room temperature for 30 minutes. Then the solution of 4-chloro-1-methyl-3-nitropyridin-2(1H)-one (3.0 g, 16 mmol) in tetrahydrofuran (50 mL) was added in one portion. The resultant solution was stirred and heated to 50° C. for 12 hours. Once starting material was consumed, the reaction solution was quenched with water (100 mL) at 0° C., and extracted with ethyl acetate (100 mL*3). The combined organic layers were washed with brine (100 mL*2), dried over anhydrous sodium sulfate, filtered and concentrated to give a residue. The residue was purified by column chromatography (silica gel, dichloromethane/methanol=10:1) to give ethyl 2-(1-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yl)-3-oxobutanoate (2.5 g, 56%) as a yellow solid. LRMS (M+H+) m/z: calcd 282.09. found 282.

Provenance & Evidence