Compounds represented by the general formula (I): ##STR00001## wherein each symbol is as defined in the description [with the proviso that 9-chloro-7-(1,1-dimethylethyl)-2,3,4,5-tetrahydro-1,4-benz-oxazepine and N-[[(5S)-2-oxo-3-(2,3,4,5-tetrahydro-1,4-benz-oxazepin-7-yl)-5-oxazol- idinyl]methyl]acetamide are excluded], salts of the same, and prodrugs thereof have selective activation effect on serotonin 5-HT.sub.2C receptor and are useful as preventive and therapeutic agents for lower urinary tract diseases, obesity, and/or pelvic organ prolapse.