Fluorinated analogues of the tricyclic neuroleptics; 7-Fluoro and 7-trifluoromethyl derivative of 10-(4-methylpiperazino)-10,11-dihydrodibenzo[b,f]thiepin

Abstract

Reaction of 3-fluorothiophenol with (2-iodophenyl)acetic acid gave the acid VIII which was cyclized with polyphosphoric acid to the ketone XII. The first title compound VI was prepared via the intermediates XV and XVIII. Treatment of the ketone XII with 1-methylpiperazine in the presence of titanium tetrachloride resulted in the enamine XXIII. The similarly prepared acid IX was cyclized to the ketone XIII. By-products were the di-acid X and the enol-lactone XXIV, affording by alkaline hydrolysis the keto acid XXV. The synthesis of the second title compound VII was carried out from the ketone XIII via the intermediates XVI and XIX. 10,11-Dihydrodibenzo[b,f]thiepin-3,11-diol (XVII) gave by treatment with methanesulfonyl chloride and by the following reaction with 1-methylpiperazine the salt of 1-methylpiperazine with dibenzo[b,f]thiepin-3-ol (XXII) and 1-methyl-4-(methylsulfonyl)piperazine (XXVI)). Whereas the compound VI has low central depressant and cataleptic activity, the corresponding enamine XXIII is very potent in both lines. The trifluoromethyl derivative VII has the character of a neuroleptic but its depressant and cataleptic activity are ten times lower than those of the 8-trifluoromethyl isomer.