2-Pyrrolidinylideneureas, a new class of central nervous system agents

Abstract
A series of N-aryl-N''-(1-methyl-2-pyrrolidinylidene)ureas was prepared and screened for pharmarcological activity in mice and rats. Congeners possessing either phenyl or phenyl substituted with 4-nitro, 3-bromo, 3-chloro, 3-fluoro and 3-methyl groups demonstrated anxiolytic activity. 2,6-Disubstitution of the phenyl ring with methyl, chloro and bromo imparted potent muscle-relaxant properties which appear to be centrally mediated. A significant separation of the anxiolytic and muscle-relaxant properties from other CNS activity, e.g. anticonvulsant, sedative and hypnotic, was achieved.