In 1903, Fischer and von Mering1 described the barbituric acid hypnotic diethylbarbituric acid (diethyl malonyl urea), introduced as Veronal. This is now official in the United States Pharmacopeia X as barbital. There were also introduced the sodium salts of barbital under the proprietary names Medinal and Veronal Sodium. Some years later a second derivative of the series was announced; in this, one of the ethyl groups was displaced by a phenyl group. This derivative, phenylethylbarbituric acid, was the proprietary designated as Luminal; the same substance is now official under the name phenobarbital.
In the meantime, numerous hypnotics of the barbituric acid series2 in which the ethyl groups are replaced by other alkyl or aryl radicals have been developed, including, among the more common ones, amytal (isoamylethylbarbituric acid), dial (diallylbarbituric acid), neonal (N-butylethylbarbituric acid), nostal (isopropyl bromallyl barbituric acid) and pentobarbital sodium.
In February, 1922, Allonal (Numal) was introduced