| ChemSpiderID = 21106365 }} | Section2 = }} Phenothiazine's an organic compound that occurs in various antipsychotic and antihistaminic drugs. It's the formula S(C6H4)2NH. This yellow tricyclic compound's soluble in acetic acid, benzene, and ether. The compound's related to the thiazine-class of heterocyclic compounds. Derivatives of the parent compound find wide use as drugs. Synthesis The compound was originally prepared by Bernthsen in 1883 via the reaction of diphenylamine with sulfur, but… (More on Phenothiazines)