Barbiturate epoxide

DJ Harvey, DB Johnson, MG Homing. Detection by gas phase analytical methods of derivatives of barbiturate epoxides. Anal Lett 5 745—755, 1972. 

Detection by Gas-Phase Analytical Methods of Derivatives of Barbiturate Epoxide... 

A few barbiturates also contain an allylic group at C(5), e.g., allobarbi-tal (10.64, R = allyl), alphenal (10.64, R = Ph), aprobarbital (10.64, R = i-Pr), and secobarbital (10.64, R = 1-methylbutyl). These compounds were substrates of the epoxide-diol pathway in rats and guinea pigs. The relative... 

The peculiar reactivity of epoxides of 5-vinylbarbiturates (10.65, Fig. 10.17) has been discussed in Sect. 10.5.3. Here, we note that hexobarbital epoxide (10.9) shows the same reactivity and decomposes via the same retro-aldol reaction to form 5-(l-methylbutyl)barbiturate [193]. 

Analytical Properties Resolution of several enantiomers of polycyclic aromatic hydrocarbons, for example, chrysene 5,6-epoxide, dibenz[a,h]anthracene 5,6-epoxide, 7-methyl benz[a]anthracene 5,6-epoxide resolution of barbiturates, mephenytoin, benzodiazepinones, and succinimides direct separation of some mono-ol and diol enantiomers of phenanthrene, benz[a]anthrene, and chrysene ionically bonded to silica gel, this phase provides resolution of enantiomers of c/s-dihydroidiols of unsubstituted and methyl- and bromo-substituted benz[a]anthracene derivatives having hydroxyl groups that adopt quasiequatorial-quasiaxial and quasiaxial-quasiequatorial conformation Reference 31-35... 

Oxidation of substituents attached to C5 is the most important pathway of metabolism for the barbiturates. The oxidative processes may yield alcohols, ketones, and carboxylic acids. For example, pentobarbital is oxidized to a hydroxy compound and a carboxylic acid (8) as shown in Fig. 5.2. The oxidative process may also yield phenols. If the barbiturate has a phenyl group attached to C5, by far the most important metabolic product is the p-hydroxyphenyl derivative, which has been shown to be formed through the intermediate epoxide (9). For example, phenobarbital is metabolized top-hydroxyphenobarbital (Fig. 5.3). The oxygenated metabolites (alcohols, phenols, ketones, and carboxylic acids) may be excreted in the urine in the free form or conjugated with glucuronic or sulfuric acid. 

S.2.2.2 Barbiturates. A major event in the field was the launching of barbital (6,5-dieth-ylbarbituric acid) in 1903 and phenobarbital (5-ethyl-5-phenylbarbituricacid)in 1912. The barbiturates dominated the field for nearly 50 years, until the launch of Librium (chlordiaz-epoxide) in 1960, the first of the benzodiazepine class drugs. Benzodiazepines completely overtook the barbiturates and had become The dominant class of sedative hypnotic drugs until the launch of retrocyclic sedative-hypnotics. 

The barbiturates may also induce epoxide hydrolase (Sipes and Gandolfi 1991), hastening the elimination of oxychlordane, a toxic metabolite of chlordane. 

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