Phenobarbital is 5-ethyl-five-phenylbarbituric acid. Phenobarbital can be a substituted pyrimidine by-product wherein the basic composition is barbituric acid, a compound that has no CNS exercise. CNS action is acquired by substituting alkyl, alkenyl, or aryl groups on the pyrimidine ring. It's the next structural system:Barbiturates are absorbed i