Diethylamine → Ethyl 2-{N,N-Diethylcarbamoyl)-2-ethylbutyrate

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Reaction Steps

To a solution of monoethyl diethylmalonate (28 g. 0.15 mole) in dry benzene (300 ml.) is added SOCl2 (15 ml., 0.21 mole) at 26°-28° C. in 2 min, with mechanical stirring. The reaction solution is gradually heated to 78° over 25 min, then is heated an additional 45 min at 85°-90°. The mixture is concentrated to dryness under reduced pressure, benzene (100 ml.) is added, and the mixture is again concentrated to dryness. The resultant oily residue dissolved in benzene (200 ml.) is treated dropwise with a solution of diethylamine (30 ml., 0.29 mole) in benzene (90 ml.) at 5°-15° over 17 min, and the reaction mixture is refluxed for 7 hours. The mixture is stored for 18 hours at room temperature and is filtered (to remove insoluble salt), is washed with benzene (50 ml.), is dried over MgSO4 and activated charcoal for 15 min, is filtered, and is concentrated to dryness under reduced pressure (bath at 50°-60°). This will yield 29 g. (79%) of ethyl 2-(N,N-diethylcarbamoyl)-2-ethylbutyrate.

Provenance & Evidence