Thioethers from phenols

A suspension of cuprous oxide promotes nucleophilic substitution in aprotic polar solvents at e. g. 150-200°. Effective nucleophiles are the anions ArO , AlkO , ArS , AlkS , CN", I, Br , and Gl phenols and thiols may be used in place of their salts.—E Thioethers from halides. 1-Bromonaphthalene and Na-thio-phenoxide heated 24 hrs. at 153° in dimethylformamide containing CugO -> 1-phenylthionaphthalene. Y 99%. F. e. s. R. G. R. Bacon and H. A. O. Hill, Soc. 1964, 1108. 

In general, EC reactions are typically observed according to the following general rank order (by relative ease of oxidation) o,p-quinol and o,p-aminophenol > tertiary amine > m-quinol rv phenol rv arylamine > secondary amine thiol > thioether primary amines, aliphatic alcohols. (HDVs) each redox active metabolite are obtained from the response across adjacent EC-Array sensors. These data are a reflection of the kinetic and thermodynamic components of electron transfer reactions. Since chemical structure is a critical determinant of an analyte s redox behavior, the intrinsic generation of an HDV with EC-Array provides qualitative information for each species. 

Boyadzhiev L, Bezenshek E, Lazarova Z. Removal of phenol from waste water by double emulsion membranes and creeping film pertraction. J Membr Sci 1984 21 137-144. Ohki A, Takagi M, Takeda T, Ueno K. Thioether-mediated copper transport through hquid membranes with the aid of redox reaction. J Membr Sci 1983 15 231-244. Wodzki R, Szczepanska G. Design of integrated membrane system with hquid and polymer membranes. Zeszyty Naukowe Pohtechniki Slaskiej, Chemia 2001 146 231-234 (in English). 

The loss of Impact strength of polypropylene was followed from sheets stored In air at 25°C and 60°C after irradiation with electron beams. A marked difference in efficacy of phenolic and thioether-based stabilizers at the two temperatures was found, with the thioether active alone at 60°C but only synergistically at 25°C. This difference was also reflected qualitatively in differences in chemiluminescence emission from the samples. 

The above considerations bear on the ambient chemiluminescence from polypropylene, although at 150°C one would still expect that the fluorescence emission from singlet carbonyls would be relatively unaffected by quenching from stabilizers in our samples. One can also infer that physical quenching alone is not sufficient to explain the decrease in light from the polypropylene sample with both phenol and thioether (Table II, comb), since the initial reduction in intensity is more than can be accounted for by the combined effects of the additives separately. 

The thioether ester (DLTDP) shows a very strong synergistic effect with the phenolic stabilizer at room temperature, and is active alone at 60°C for protection from loss of impact strength of the irradiated polypropylene. 

Kawahara (51) found that he could identify spilled asphalts by making the pentafluorobenzyl thioethers and ethers from traces of mer-captans and phenols in asphalts, and separating them by gas chromatography, using an electron capture detector to obtain the distinctive chromatograms. 

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