A comparison of the antiserotonin, antihistamine, and anticholinergic activity of cyproheptadine with analogues having furan nuclei fused to the 10,11-vinylene bridge.

A series of cyproheptadine derivatives having furan nuclei fused to the 10,11-vinylene bridge has been prepared. None of the compounds retain the potent antiserotonin and antihistaminic actions of cyproheptadine. 1-methyl-4-(1-methyl-8H-dibenzo[a,e]furo[3,4-c]cyclohepten-8-ylidene)piperidine (7), 1-methyl-4-(1,3-dihydro-1-oxo-8H-[3,4:6,7]cycloheptal[1,2-c]furan-8-ylidene)piperidine (10), and its reduction product 11 retained the peripheral anticholinergic activity of cyproheptadine.