ALKYL THIOETHER ACTIVATION OF THE NITRO DISPLACEMENT BY ALKANETHIOL ANIONS - USEFUL PROCESS FOR THE SYNTHESIS OF POLY[(ALKYLTHIO)BENZENES]

The reactions of o-and p-dinitrobenzenes, 2, 4-dinitro-l-chlorobenzene, picryl chloride, and other simple halogenonitrobenzenes, with an excess of the sodium salt of the isopropanethiol, in HMPA, afforded the products of complete displacement of all the chloro and the nitro groups present in the molecule. These results indicated that the thioether function in the ortho or para positions activates the substitution of the nitro group by the alkanethiolate anion. The effect of the structure of the thiolate was examined by effecting the same reactions, in HMPA, with MeSNa, EtSNa, Me3CSNa, and PhSNa. Reactions with Me2CHSNa were also carried out in DMF and Me2SO. It was observed that the reduction of the nitro group competes with the displacement process and that the relative importance of the two reactions depends on the structure of the aromatic substrate and of the thiolate as well as on the solvent employed. Complete and clean substitution reactions were obtained only with Me2CHSNa in HMPA. © 1979, American Chemical Society. All rights reserved.