Urea → Octyl barbituric acid

Participants

Reaction Steps

To a solution of sodium (5.32 g) in 400 ml of anhydrous ethanol is added a solution of diethyl 2-octylmalonate (31.5 g) in 50 ml of ethanol and successively 10.27 g of urea, then the mixture is refluxed for 2 hours 30 minutes. The mixture is rapidly cooled to room temperature and the solid which was formed is recovered by filtration and washed with diethyl ether. The solid is then dissolved in 200 ml of water and acidified with 6 N hydrochloric acid until pH 1.5-2 is reached. A solid separates. The mixture is added with 200 ml of ethyl acetate and it is stirred for 2 hours, then it is added with additional 800 ml of warm ethyl acetate. The organic phase is separated and the aqueous phase is washed with 200 ml of ethyl acetate. The pooled organic phases are washed with 250 ml of saturated aqueous solution of sodium chloride dried over sodium sulfate and concentrated to dryness. 21.03 g of the product are obtained.

Provenance & Evidence