Oxygen thiophenol

Positional changes of the exocyclic oxygen atom in 157b and 158b discriminate between the reactivity of these compounds. Thus, 158b readily reacts with the potassium salt of thiophenol to give sulfide 177 in 85% yield (83JHC783),... 

The oxygen atom in these molecules can in many cases be dispensed with as well substitution of sulfur for nitrogen affords a molecule whose salient biologic properties are those of a sedative and tranquilizer. Friedel-Crafts acylation of the n-butyl ether of thiophenol with benzoyl chloride gives the corresponding benzophenone. Reduction of the ketone (15) followed by... 

Kharasch and coworkers were the first to show that thiols and olefins cooxidize in an atmosphere of oxygen at room temperature to yield substituted 2-sulphinylethanols 81 (equation 45). Later on, it was demonstrated that a-mercapto-substituted hydroperoxides are formed as intermediates. Thus, Oswald found that cooxidation of thiophenol with styrene gave the corresponding 8-mercaptohydroperoxide 82 which subsequently underwent rearrangement to 2-phenylsulphinyl-a-phenylethanol 83 (equation 46). 

Homolytic hydrostannation can also be initiated at room temperature by thiophenols, when a trace of oxygen may oxidize the thiol to the ArS radical, which abstracts hydrogen from the stannane to give the stannyl radical (Equation (15)).93 With azoisobutyronitrile (AIBN) initiation, alkynes undergo only monohydrostannation, but with the thiol, simple alkynes show bis(hydrostannation) or bis(stannation). 

In all cases, the oxidation rate was smallest for experiments involving thiophenol and ferf-butanethiol. The oxygen uptake vs. time curves for cobalt-catalyzed reactions showed an initial high slope followed by a decrease in slope after ca. 30% reaction to a final steady value. 

Substituted and condensed thiophenes and thiophenols are usually the most abundant sulfur-containing compounds in refined fuels. These compounds are known to react with oxygen to form peroxides and eventually result in color bodies and gumlike fuel deposits. The reaction of thiophenol with a free-radical compound and oxygen is shown below ... 

The equivalence of sulfur and oxygen in this ring system carries over to NSAIDs as well. Preparation of the sulfur analogue of isoxepac (6-4) starts with the alkylation of thiophenol (27-1) with benzyl chloride (26-1). Cyclization of the intermediate thioether (27-2) then affords the homothioxanthone (27-3). The carboxyl side chain is then extended by means of the Amdt-Eistert homologation reaction. The acid is thus hrst converted to its acid chloride by means of thionyl chloride. Reaction with excess diazomethane leads to the diazoketone (27-4). Treatment of that intermediate with silver benzoate and triethylamine leads the ketone to rearrange to an acetic acid. There is thus obtained tiopinac (27-5) [28]. 

According to Kanter the reaction sequence 164 to 169, i carried out in the presence of trifluoroacetic acid and thiophenol with the careful exclusion of oxygen, leads to a 40% yield of l-dimethylamino-l-phenoxy-2.4.6-triphenyl- -... 

Co-oxidation of indene and thiophenol takes place readily if the reactants in benzene solution are shaken with oxygen at temperatures in the range 20° to 40°C. (7). The major primary product has been shown to be frans-2-phenylmercapto-1 -indanyl hydroperoxide, I, which rearranges spontaneously to the two racemes of frans-2-phenylsulfinyl-l-indanol, II (8), and a tentative reaction scheme involving a three-step radical chain based on the suggestion of Kharasch, Nudenberg, and Mantell (11) was proposed for the formation of I. These three products accounted for 86% of the oxygen absorbed. 

Examination of Co-Oxidation Products. Co-oxidation products were identified and hydroperoxide and sulfoxide yields were measured as previously described (7, 8). The observed stoichiometric ratio of indene, thiophenol, and oxygen consumed in the whole reaction is 1 1.06 1 (8). 

Co-Oxidation in absence of Added Catalysts or Inhibitors. Figure 1 (curves A,A, B,B ) shows typical oxygen uptake vs. time curves obtained after using the procedures for purifying indene, thiophenol, and benzene and cleaning the reaction vessel as described above. On the experience of several hundred runs, the reproducibility expected was such that the time for uptake of 0.5 mole of 02 per mole of PhSH would be in the range 150 to 200 minutes. Despite all efforts, it was estimated that iron... 

Co-Oxidation in Presence of Added N,N -di-sec-butyl-/>-phenylene-diamine. Figure 3 shows typical oxygen uptake curves obtained if DSBPD is added at concentrations around 10"2 to 10 4M to the indene-thiophenol reaction mixture. The reproducibility was good. The products after oxygen absorption was complete and the hydroperoxide had been allowed to decay were substantially the same as those obtained in the absence of DSBPD. Uptake of oxygen was extremely slow when either of the main reactants was omitted. 

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