Received June I, 1965 4 series of compounds related to cyproheptadine has been prepared and the antihistaminic and antiserotoniri properties were studied. replacement of the methyl on nitrogen by other groups, introduction of halogen substituents in the aromatic nucleus, saturation of the 5, a or the 10, ll double bond, and replacement of the dibenzocycloheptene nucleus by xanthene, thioxanthene, or fluorene systems. The antihistaminic and ...