Manufacturing Process
5-sec-Butyl-5-ethylbarbituric acid was prepared from diethyl ester of malonic
acid in 3 steps. At the above malonic ester was reacted with C2H5Br and
sodium ethylate producing the diethyl ester of ethylmalonic acid, which after a
reaction with sodium ethylate and 2-butylbromide gave the ethyl-(2-butyl)-
malonic acid diethyl ester. The last one produced the 5-sec-butyl-5-ethylbarbituric
acid after a reaction with urea and sodium ethylate.
23 g sodium (1 mol) was dissolved in 300 ml alcohol. To this solution was
added a solution of 5-sec-butyl-5-ethyl-barbituric acid (1 mol) in 800 ml
alcohol. To a mixture was added 1000 ml benzene, which precipitated the
sodium salt of the barbituric acid (butabarbital sodium). The product was
filtered and dried.
