Methyl sulfones, dimethyl carbonate reaction

Directed lithiation of aromatic compounds is a reaction of broad scope and considerable synthetic utility. The metalation of arenesulfonyl systems was first observed by Gilman and Webb and by Truce and Amos who reported that diphenyl sulfone is easily metalated at an orf/io-position by butyllithium. Subsequently, in 1958, Truce and coworkers discovered that metalation of mesityl phenyl sulfone (110) occurred entirely at an orf/io-methyl group and not at a ring carbon, as expected. Furthermore, refluxing an ether solution of the lithiated species resulted in a novel and unusual variation of the Smiles rearrangement and formation of 2-benzyl-4,6-dimethyl-benzenesulfinic acid (111) in almost quatitative yield (equation 78). Several other o-methyl diaryl sulfones have also been shown to rearrange to o-benzylbenzenesulfinic acids when heated in ether solution with... 

In a 500 ml three-necked flask, fitted with stirrer, thermometer, and water trap, 5.71 g (25 mmol) of bisphenol A are dissolved in a mixture of 60 ml dry dimethyl sulfoxide and 30 ml dry toluene. After thorough flushing with nitrogen, 7.0 g (50 mmol) potassium carbonate are added. The mixture is then heated under stirring at 170°C for 4 h, in order to remove the water by azeotropic distillation with toluene. Then 7.18 g (25 mmol) of 4,4 -dichlorodiphenyl sulfone are added to this suspension. After further 10 h at 170°C, the reaction mixture is cooled, diluted with 100 ml of THF followed by careful addition of 80 ml of concentrated hydrochloric acid. The aqueous phase is extracted repeatedly with THF. Phase separation is induced by addition of small amounts of methyl tert-butyl ether. The organic phases are collected and concentrated. This viscous solution is slowly dropped into 3 1 of distilled water with intensive stirring, whereupon the polymer precipitates. After... 

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