Abstract

1. Additional evidence, from studies of the comparative central actions of phenyl alkenyl barbituric acids, is presented to show that the mechanism which raises the convulsant threshold is different from the mechanism producing hypnosis.

2. Anticonvulsant activity of the phenyl alkenyl barbituric acids appears to be maximal with the four-membered straight alkyl chain compound, 5-phenyl-5-crotyl barbituric acid.

3. The phenyl crotyl compound is more soluble in water than the corresponding phenyl butyl compound, and is more effectively absorbed after oral administration, when both are given in the form of their free acids.