Diethyl Oxalate → Ethyl 3-{2-[2-(dipropylamino)ethyl]-6-nitrophenyl}-2-oxopropanoate

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Reaction Steps

To a solution of 2.38 g (0.103 gram atoms) of sodium metal in 52 cc of absolute ethanol at room temperature was added 18.51 g (0.07 mole) of the nitro compound in one portion, with stirring, followed by 15.42 g (0.103 mole) of diethyl oxalate. The reaction was refluxed under nitrogen for about 20 minutes, cooled, quenched on 700 cc of ice-water and acidified with 3N hydrochloric acid. This aqueous solution was washed with a small volume of ether, basified to pH 8.5 with solid sodium carbonate and extracted with 3 portions of ether. The combined ether extract was washed with saturated brine, dried over anhydrous magnesium sulfate, clarified with charcoal and concentrated in vacuo. The residue was triturated with cold petroleum ether, filtered and air-dried to give 6.0 g of ethyl 6-(2-di-n-propylaminoethyl)-2-nitrophenylpyruvate as a yellow powder. The triturate was concentrated in vacuo and distilled to give 7.3 g of recovered starting material which was recycled. In the same manner, a total of three recycles provided 11.0 g of ethyl-6-(2-di-n-propylaminoethyl)-2-nitrophenylpyruvate.

Provenance & Evidence