Sulfones benzenesulfonic anhydride

In glucosides, hemiacetal hydroxyl activation/substitution can be achieved using a sulfonic anhydride and a nucleophile, plus a base as acid scavenger.12 The reaction is catalysed by dibutyl sulfoxide (Bu2S=0), and shows evidence of sulfur-covalent catalysis. Using benzenesulfonic anhydride [(PhS0)20], it is proposed to involve initial formation of a sulfonium sulfonate (6), the S(IV) centre of which then reacts with... 

Sulfonic anhydrides are prepared from acid chlorides, in principle, by the same methods as are used for the corresponding carboxylic anhydrides. Thus Billeter692 obtained alkanesulfonic anhydrides by the action of the sulfonyl chlorides on silver alkanesulfonates benzenesulfonic anhydride is best obtained by heating 2 moles of benzenesulfonyl chloride and 1 mole of anhydrous oxalic acid slowly to 200°.693... 

General Reactions. Arenesulfonic anhydrides have been used as precursors for a variety of substituted sulfones, sulfonate esters, and sulfonamides. The Friedel-Crafts reaction of benzenesulfonic anhydride and benzene in the presence of AICI3 provided diphenyl sulfone in 99% yield (eq 1). This has proved to be milder and more efficient than the similar reaction using benzenesulfonyl chloride. ... 

Sulfonic acids are converted to the corresponding acid halides in much the same way as carboxylic acids. Thionyl chloride is the best reagent for the preparation of methanesulfonyl chloride (83%). By heating with a large excess of thionyl chloride, however, p-toluenesulfonic acid is converted into its anhydride (87%). Benzenesulfonyl chloride is made in 80% yield by the action of either phosphorus pentachloride or phosphorus oxychloride at 180° on sodium benzenesulfonate. Chlorosulfonic and fluorosulfonic acids are used in the conversion of sodium p-chloro-benzenesulfonate to the corresponding sulfonyl halides (85 8S>%). ... 

Inhibiting Side Reactions. As stated in a preceding section, undesired by-product sulfone formation is pronounced in the mono- and disulfonation of ai matic hydrocarbons such as benzene, toluene, or xylene with SO or strong oleum. The addition of acetic acid (about 5 per cent by weight of the hydrocarbon) inhibits, but does not eliminate, sulfone formation. Sodium sulfate and sodium benzenesulfonate are also said to inhibit sulfone formation from benzene. In sul nating dodecylbenzene detergent alkylate with SO3, sulfone formation does not occur as it does with benzene or toluene, but sulfonic anhydride formation does occur. This objection-... 

Benzene (Table I, p. 165). Some of the factors involved in the industrial sulfonation of benzene have been discussed. In the small-scale, laboratory preparation, where the difference in cost between sulfuric acid and oleum is negligible, oleum is the preferred reagent. Benzene is added gradually to ice-cold sulfuric acid containing 5-8% of the anhydride the reaction is complete after ten to fifteen minutes. Benzensul-fonic acid is isolated readily as the sodium salt by the addition of the reaction mixture to a saturated sodium chloride solution. The reaction of benzene with chlorosulfonic acid is not used for the preparation of benzenesulfonic acid because, under conditions that limit the formation of the sulfonyl chloride, the acid is always accompanied by phenyl sulfone. Benzenesulfonyl chloride can be obtained in a yield of 75-77% by the addition of benzene to an excess of chlorosulfonic acid (room temperature). Fluorosulfonic acid reacts less vigorously the addi-... 

A vigorous stream of acetylene passed for 2 hrs. through a soln. of benzene-sulfonic acid and yellow HgO in dioxane-acetic anhydride with efficient stirring and cooling below 37 vinyl benzenesulfonate. Y 48%.—Benzene may be used as a diluent. F. e. s. H. Hopff and H. Lussi, Helv. 42, 2742 (1959). 

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