Pharmacological studies on CS-430, a new psychotropic agent.

10-Bromo-11b-(2-fluorophenyl)-2,3,7,11b-tetrahydrooxazolo[3,2-d][1,4]benzodiazepin-6(5H)-one (CS-430) is a new psychotropic drug and has the following properties. The compound showed sleep-inducing effect at both 0.2 and 5 mg/kg (p.o.) in cynomolgus monkeys or at 3 mg/kg (p.o.) in rats. CS-430 showed selective conflict attenuating in rats or anticonvulsant effects in mice. Furthermore, CS-430 blocked non-discriminated (Sidman) avoidance response without severe impairment of the motor function but not discriminated (shuttle-box) avoidance response in rats. CS-430 also blocked selectively electroshock-induced fighting behavior of mice but not isolation-induced fighting behavior of mice and muricidal behavior induced by ablation of the olfactory bulbs. In addition, CS-430 produced specific potentiation of chlorprothixene-induced sleep and particular potentiation of thiopental sleep in mice. These effects of CS-430 were similar to those of nitrazepam, but differed from those of phenobarbital. The effect of CS-430 on the motor function was roughly 1/2 as potent as that of nitrazepam in the various tests.