Fluorinated tricyclic neuroleptics with prolonged action: 3-Fluoro-8-trifluoromethyl derivatives of 10-(4-methylpiperazino)- and 10-[4-(2-hydroxyethyl)piperazino]-10,11-dihydrodibenzo-[b,f]thiepin

A reaction of (4-fluoro-2-iodophenyl)acetic acid with 4-(trifluoromethyl)thiophenol gave the acid VIII which was cyclized with the reagent consisting from methanesulphonic acid and phosphorus pentoxide and afforded the methanesulphonic enol ester XIX. The alkaline hydrolysis resulted in 3-fluoro-8-trifluoromethyldibenzo[b,f]thiepin-10(11H)-one (XVI) which was transformed via the alcohol XXIV to the chloro derivative XXV. Substitution reactions with 1-methylpiperazine and 1-(2-hydroxyethyl)piperazine resulted in the title compounds IV and V. These products are very potent cataleptic neuroleptic agents with a prolongation of duration of the effects comparable to that of isofloxythepin and tefluthixol. A series of further synthetic experiments aimed at alternative syntheses of the acid VIII and the ketone XVI; their results were mostly not of use for preparative purpose but they led to isolation and characterization of a series of interesting heterocyclic products (XVII, XVIII, XXII, XXIII, XXIX-XXXI, XXXVI-XXXIX).