We developed new intravenous sedative-hypnotic compounds with the isoindolin-1-one skeleton focusing on the water-soluble property and in vivo safety. We synthesized approximately 170 derivatives and evaluated their hypnotic effects by intravenous administration of the compounds to mice. A series of the 2-phenyl-3-[2-(4-methyl-1- piperazinyl)-2-oxoethyl] isoindolin-1-one analogs, 3 (−), 5 (−), 27 (−), and 47 (−)[JM-1232 ( ...