Abstract

1. Hypnosis is a property quite common to the ureas.

2. With respect to hypnotic effectiveness, in the alkly ureas molecular weight is a determining factor, as with the aliphatic alcohols.

3. In general, in the aliphatic ureas, the hypnotic potency decreases in the following order; monoalkyl ureas, symmetrical dialkyl ureas (methyl series), unsymmetrical dialkyl ureas, symmetrical dialkyl ureas (ethyl series) and trialkyl areas. The toxicity values are not consistent, thus making generalization concerning this property difficult.

4. In the aryl and alkylaryl ureas, molecular weight is not an important factor in determining hypnotic effectiveness. In these series, the position of a substituent group in position isomers is more important.