The syntheses of 2-amino-N-(2-benzoyl)-4-chlorophenyl)acetamides are reported. The pharmacological properties of these compounds were compared with data obtained from the corresponding cyclized products [5-(2,6-dichlorophenyl)-1,4-benzodiazepin-2-ones]. Evidence is presented which suggests that the central nervous system activity observed for 1,4-benzodiazepines is inherent only in the closed seven-membered ring and is not due to the ring-opened form.