Identification of a potent and selective 5-HT6 antagonist:: One-step synthesis of (E)-3-(benzenesulfonyl)-2-(methylsulfanyl)pyrido[1,2-a]pyrimidin-4-ylidenamine from 2-(benzenesulfonyl)-3,3-bis(methylsulfanyl)acrylonitrile

(E)-3-(Benzenesulfonyl)-2-(methylsulfanyl)pyrido[1,2-alpha]pyrimidin-4-ylidenamine (7) was found to be a potent and selective 5-HT6 antagonist. A one-step synthesis of this compound is described.