Bisaryl cyclic ureas have been identified as high affinity 5-HT 2C receptor antagonists with selectivity over 5-HT 2A and 5-HT 2B . Compounds such as 8 and 22 have shown oral activity in a centrally mediated pharmacodynamic model of 5-HT 2C function in rodents. ... A series of novel bisaryl imidazolidinones have been prepared and evaluated both in vitro and in vivo for their 5-HT 2C receptor antagonist activity. ... The 5-HT 2 superfamily consists of three subtypes, namely, ...