Stereoselective blockade of the dopamine receptor and the X-ray structures of α and ß-flupenthixol

Abstract

THE introduction of neuroleptics of the phenothiazine and thioxanthene classes has revolutionised the treatment of schizophrenia and there is increasing evidence1-3 that links this antipsychotic action to a blockade of dopamine receptors in the brain. The thioxanthene compounds are of particular interest as, because of the presence of an exocyclic double bond and a substituent in the tricyclic nucleus, they exist as cis-trans geometric isomers about the double bond with respect to the ring substituent (Fig. 1). Virtually all the neuroleptic activity is confined to the cis isomer 4. © 1975 Nature Publishing Group.