Diphenyl sulphone

Most of the examples concern substituted diphenyl sulphones, with the anti-leprotic agent 4,4 -diaminodiphenyl sulphone taking a prominent place. Cates and Meloan56 separated aliphatic, aromatic and cyclic sulphones using helium carrier gas and thermal... 

Olah and coworkers56 found that treatment of dialkyl, arylalkyl and diaryl sulphides with nitronium hexafluorophosphate (or tetrafluoroborate) 32 at —78° in methylene chloride resulted in the formation of sulphoxides in moderate to high yields (Table 3). In the oxidation of diphenyl sulphide which affords diphenyl sulphoxide in 95% yield, small amounts of the ring nitration products (o- and p-nitrophenyl phenyl sulphides) were formed. However, diphenyl sulphone and nitrophenyl phenyl sulphoxide were not detected among the reaction products. 

The first report of the use of bromine for the oxidation of sulphoxides appeared in 1966116. Diphenyl sulphone was isolated in 0.5-1% yield when the sulphoxide was treated with bromine in aqueous acetic acid for several hours. The yield was increased to about 5% by quenching the reaction with sodium carbonate. A kinetic study117 of a similar reaction involving dimethyl sulphoxide showed no significant yield improvement but postulated that the mechanism proceeds via an equilibrium step forming a bromosulph-onium type intermediate which reacted slowly with water giving dimethyl sulphone as indicated in equation (35). 

Consequently, in conducting aprotic media, most of the diaryl sulphones follow the scheme written below for diphenyl sulphone ... 

Dimethyr diphenyl sulphone 4,4 -Dimethyl" diphenyl sulphone... 

Evidence for the formation of alkyl and aryl radicals in some cases following loss of SO2 (Scheme 1) has been obtained. Thus, a small amount of M-pentane was formed in the decomposition of M-pentanesulphonyl azide in mineral oil ). Thermolysis of diphenyl sulphone-2-sulphonyl azide (8) in dodecane at 150 °C gave diphenyl sulphone 9 (27%) and diphenyl sulphone-2-sulphonamide 10 (9%) which arise by hydrogen abstraction by the aryl radical and sulphonyl nitrene, respectively. When this thermolysis was carried out in Freon E-4 at 150 °C, the products were diphenylene sulphone 77 (1.3%) (Pshorr-type cyclization product of the aryl radical) and 10 (1.5%) together with tars 16h Ferro-... 

Dialkyl sulphones are not reducible at a mercury cathode. Aryl alkyl and diaryl sulphones are however reduced with cleavage of a carbon-sulphur bond. Polaro-graphic half-wave potentials for this process are given in Table 5.6. One-electron addition in aprotic media to phenyl methyl sulphone [66] and to diphenyl sulphone [67] leads in both cases to a delocalised radical-anion in which the sulphone grorqj can be described as contributing a vacant symmetrical dx-orbital to the conjugated system. Phenyl methyl sulphone radical-anion is prepared and characterised in liq-... 

Scheme 5.2. Pathways propo-sed for the reduction of diphenyl sulphone in dimethylsulphoxide...

Reaction of both methyl phenyl sulphone and diphenyl sulphone with potasium in liquid ammonia [24] leads to the formation of a dianion, which cleaves to give CfiHs, isolated as benzene. The initial electron transfer cannot be dissociative, as was the case for diethyl phenyl phosphate (p. 163), since the phenyl c-radical is not detected. The radical-anions from these sulphones have sufficiently long lifetime in liquid annmonia to allow reaction with a further electron. 

Diglycidyl ether of resorcinol 4,4 -Diamino-diphenyl sulphone 112 3 49)... 

Diphenyl sulphone [127-63-9] M 218.3, m 125 , b 378 (dec). Crystd from ethyl ether. Purified by zone melting. 

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