Synthesis of potential neuroleptics and tranquillizers: 2-(tert.Amino)-9-(3-dimethylaminopropylidene)thioxanthenes

Abstract

4-Dimethylamino-, 4-pyrrolidino-, 4-piperidino-, 4-morpholino- and 4-(4-methylpiperazino)-thiophenol (IIIa-IIIe), which were prepared by two methods and characterized as the 2,4-dinitrodiphenyl sulfides IVb-IVe, were transformed by treatment with 2-iodobenzoic acid and copper in aqueous potassium hydroxide to 2-(4-tert.aminophenylthio)benzoic acids (Va-Ve). Cyclization with polyphosphoric acid gave thioxanthones VIa-VIe which were treated with 3-dimethylaminopropylmagnesium chloride to give the diamino alcohols VIIa-VIId. VIIa, VIIc and VIId were dehydrated by heating with dilute sulfuric acid which resulted in mixtures of geometrical isomers of the olefinic bases Ia, Ic and Id. Crystallization of bases or salts led to homogeneous or almost homogeneous (Z)-isomers belonging to the active chlorprothixene series. The products are devoid of cataleptic and antiapomorphine activities and show only some properties of mild tranquillizers