Triketopyrimidines The Barbiturates

The barbimrate sedative-hypnotic agents arguably constitute the oldest class of medicinal agents whose synthesis was not prompted by some biologically active natural product. The first compound in this series, barbital (67-3) (R = = Et), has 

The straightforward step used to form the ring system means that the chemistry involved in the preparation of the scores of barbiturates that have been used clinically in fact devolves on the syntheses of the various malonic esters. It should be noted that little success has been achieved in changing the side effect spectrum of these dmgs. The main differences between the various agents involve their pharmacokinetic properties these in turn are manifested as variations in bioavailablity by parenteral and oral routes as well as in time to the onset and duration of action. 

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