Hydrogen Bromide → 5-Ethyl-5-(3-bromopropyl)barbituric acid

Beteiligte Stoffe

Reaktionsschritte

A suspension of 40 g of 5-ethyl-5-allylbarbituric acid and 800 ml of toluene was stirred and irradiated with a GE sunlamp (275 watts, 110-125 volts) for approximately 90 min. Thereafter, gaseous HBr was passed for 45 min. with further irradiation and stirred for another 45 minutes. The reaction flask was then opened to allow the excess HBr to evaporate. The solution was cooled and filtered. The resulting precipitate was washed with toluene, dried, and then dissolved in a minimal amount of hot acetone. Petroleum ether (60°-68° C.) was added until a small amount of precipitate appeared; the flask was left overnight at 23° C. The crystals were filtered, washed with petroleum ether, and air dried. The melting point was 138°-140° C.

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