Pharmacological Properties of Some New N‐substituted Barbituric Acid Derivatives

Summary. In a new series of ultra short‐acting barbiturates of the general formula R1 CO‐NH C CO R2 CO‐N CH2 COOC2H5 no definite relationship was found between chemical structure and pharmacological efficiency in rats. There was no correlation between the properties potency, toxicity, duration of action, incidence and induction time. They are independent qualities and must lie treated separately. The logarithm of the time for duration of action showed normal distribution and all calculations were performed on logarithmic values. The non‐reactors formed a group, significantly separated from those where narcosis succeeded. Hexobarbitone (Evipan) was used as a reference standard and it was injected into all animals to control that there was no heterogeneity. The significance of the differences in the qualities examined between two derivatives was tested by t‐analysis. Table I give the details of the results obtained.