To identify potent and selective 5-HT2C receptor agonists, a series of novel benzazepine derivatives were synthesized, and their structure–activity relationships examined. The compounds were evaluated for their 5-HT2C, 5-HT2A, and 5-HT2B receptor binding affinity and intrinsic activity for the 5-HT2C and 5-HT2A receptors. Among these compounds, 6, 7- dichloro-2, 3, 4, 5-tetrahydro-1H-3-benzazepine (6) was effective in a rat penile erection ...