The compound t-butyl (S)-8-bromo-11,12,13,13a-tetra-hydro-9-oxo-9H-imidazo¢1,5-a!pyrrolo¢2,1-c!¢1,4!benzo-diazepine-1-carboxylate of the formula <IMG> can be used in the treatment of psychotic disorders of human beings, especially of schizophrenia, and the prevention of exacerbations thereof. It can be used as a single therapeutic agent or in combination with neuroleptics such as haloperidol.
ANTI-PSYCHOTIC IMIDAZOBENZODIAZEPINE