Allyl bromide → HCID 20532011, compound

Participants

Reaction Steps

Into a one liter three-neck flask equipped with mechanical stirrer, reflux condenser and a dropping funnel, were placed 100 g. of 5-(1-ethoxycarbonylisopropyl)barbituric acid, 100 mg. of calcium sulfate, 50 mg. of copper dust and 500 ml. of water. The mixture was stirred at room temperature for 15 minutes and 53.6 g of allyl bromide were added in one portion followed by the dropwise addition of 125 ml. of 20% sodium hydroxide over 45 minutes at 50°-55°. After stirring at 50°-55° for 3 hours, the reaction mixture was cooled to about 30° and an additional 26.8 g. of allyl bromide were added in one portion. The reaction mixture was heated with stirring, for 90 minutes, and a solution (65-70 ml.) of 20% sodium hydroxide was then added at a rate such that the reaction mixture was always slightly alkaline. The mixture was cooled to room temperature. The pH of the mixture was adjusted to about 9 by the addition of 20% sodium hydroxide and the mixture was extracted with 4 × 250 ml. of ethyl acetate. The combined ethyl acetate extracts were re-extracted with 4 × 300 ml. of 1% sodium hydroxide and the aqueous extracts were added to a mixture of 500 g. of ice and 300 ml. of 6N hydrochloric acid. The precipitate which formed upon standing at room temperature overnight was collected to give 91.0 g. (78%) of the alkylbarbituric acid, m.p. 112°-114°.

Provenance & Evidence