Two series of 8-chloro-2, 3, 4, 5,10,11-hexahydro-11-substituted-1H-dibenzob,e 1,4 diazepine-1-ones and their3,3- dimethyl analogs were prepared via internal Mannich reaction of 3-[(2- amino-4- chlorophenyl) amino] -2-cyclohexen-1-one and its 5,5-dimethyl analog, respectively, with different aldehydes at room temperature. The synthesized compounds were evaluated for their clozapine-like properties. The structures of the novel compounds were confirmed using elemental analyses and different spectroscopic methods. Pharmacological evaluation of some of the synthesized dibenzodiazepine derivatives revealed that compounds 4 and 17 (having 4-bromophenyl moiety) exhibited a high antipsychotic and sedative properties.