Abstract Acids IIa-c were prepared by reactions of (4-fluoro-2-iodophenyl) acetic acid with 4- methoxythiophenol, 4-ethoxythiophenol and 4-(ethylthio) thiophenol and cyclized with polyphosphoric acid in boiling toluene to dibenzo [b, f] thiepin-10 (11H)-ones IIIa-c. Reduction with sodium borohydride afforded the alcohols IVa-c which were treated with hydrogen chloride and gave the chloro derivatives Va-c. Substitution reactions with 1- ...