Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The 6-nitro derivative V, obtained by nitration of 3,4-dichlorobrombenzene, was transformed via the amine VI and nitrileVII to 2-bromo-4,5-dichlorobenzoic acid (IX). Its reaction with thiophenol in 3-methyl-1-butanol in the presence of potassium carbonate and catalytic amounts of copper and cuprous iodide afforded 4,5-dichloro-2-(phenylthio)benzoic acid (Xa) which was reduced to the alcohol XIa. The transformation to the homologous acid XIVa proceeded via noncharacterized intermediates XIIa and XIIIa. The cyclization with polyphosphoric acid at 150 °C resulted in 2,3-dichlorodibenzo[b,f]thiepin-10(11H)-one (XV) which was reduced to the alcohol XVI. Treatment with hydrogen chloride gave the unstable chloro derivative XVII whose substitution reaction with 1-(2-hydroxyethyl)piperazine led to the title compound II. Its dimethanesulfonate showed properties of a little toxic and noncataleptic tranquillizer. Because it does not influence the dopamine metabolism in rat brain in a rather high dose, it cannot be considered a neuroleptic.