Arenesulfonyl chlorides, sulfonylation with

This procedure represents the most convenient synthesis of 3(5)-aminopyrazole. It employs readily available starting materials and gives excellent yields in all steps.5,6 />-Toluene-sulfonyl chloride can be replaced by other arenesulfonyl chlorides. 3-Imino-l-arylsulfonylpyrazolidines can be alkylated with dimethyl sulfate or with alkyl 7>-toluenesulfonates in dimethyl-formamide to give salts of l-alkyl-2-arylsulfonyl-5-amino-4-... 

In what was intended as another experimental probe to ascertain whether a concerted or stepwise mechanism was involved in substitution reactions of arenesulfonyl chlorides, Rogne (1975) measured the enthalpies of transfer from propanol to acetonitrile for the transition states, SAH, for the reaction of imidazole with (a) benzoyl chloride and (b) benzenesulfonyl chloride. He found that SAH was considerably more negative for the reaction involving the sulfonyl chloride than for the one involving benzoyl chloride. This means that the transition state for attack of imidazole on benzenesulfonyl chloride is considerably better solvated by acetonitrile relative to its solvation by propanol... 

The reactions of metal substituted carbodiimides 20 with arenesulfonyl chlorides or arene-sulfonyl isocyanates produce metal substituted N-sulfonylcarbodiimides 21 (R3M=Me3Si, Et3Ge, Bu3Sn X=C1, NCO). ... 

Desuffouylatiou. Arenesulfonyl chlorides and bromides ate catalytically de-sulfonylated by this rhodium complex by distillation (with or without nitrogen) or by heating in hexachlorobenzetle. Yields are in the range 70-90%. 

Such uncatalyzed solvolytic processes are synthetically unimportant as a procedure for making esters, for example, the reaction is usually highly inefficient because of the tendency of these esters to alkylate an alcohol about as fast as the sulfonyl chloride sulfonylates an alcohol, and so by the time the starting material is consumed, extensive further reaction of the product will have occurred. On the other hand, the promotion of esterification by tertiary amines is a routine synthetic procedure with both arenesulfonyl and alkanesulfonyl species. 

For the preparation of arenesulfonamides from the sulfonyl chlorides by aqueous ammonia Huntress and Carten217 give the following general directions The arenesulfonyl chloride (0.5 g) is heated for 10 min with ammonia solution of d 0.9 (5 ml), then cooled to room temperature and treated with water (10 ml). The amide that separates is collected, washed thoroughly, recrystallized to constant m.p. from aqueous ethanol, and dried at 105°. 

Sulfonic acid esters are prepared by the reaction of an alkane- or arenesulfonyl chloride with an alcohol or phenol. Two of the most common sulfonyl chlorides are p-toluenesulfonyl chloride, abbreviated TsCl, and methanesulfonyl chloride, abbreviated MsCl (Section 18.1A). 

The three steps 32-34 have been suggested77 to be equilibria, and the overall equilibrium must lie far to the left because no adduct 23 is found in the reaction mixture when the reaction of sulfonyl chloride with olefin is carried out in the absence of a tertiary amine. A second possible mechanism involving oxidative addition of the arenesulfonyl halide to form a ruthenium(IV) complex and subsequent reductive elimination of the ruthenium complex hydrochloride, [HRulvCl], was considered to be much less likely. 

The HC1 generated in this reaction destroys one equivalent of diazomethane. This can be avoided by including a base, such as triethylamine, to neutralize the acid.74 Cyclic z-diazoketones, which are not available from acyl chlorides, can be prepared by reaction of an enolate equivalent with a sulfonyl azide. This reaction is called diazo transfer 5 Various arenesulfonyl azides76 and methanesulfonyl azide77 are used most frequently. Several types of compounds can act as the carbon nucleophile. These include the anion of the hydroxymethylene derivative of the ketone78 or the dialkylaminomethylene derivative of... 

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