Arylsulphonate esters

The preparation of arylsulphonate esters from arylsulphonyl chlorides (Expt 6.46). 

For this reason the arylsulphonate esters find use as alkylating agents (cf. dimethyl sulphate and dialkyl sulphates, Section 4.2.24, p. 430). 

Preston, J. S. du Preez, A. C. Solvent extraction of nickel from acidic solutions using synergistic mixtures containing pyridinecarboxylate esters. 3. Systems based on arylsulphonic acids. J. Chem. Technol. Biotechnol. 1998, 71, 43-50. 

One preparative procedure for achieving this reaction involves the acylation of the magnesium enolate of diethyl malonate with an acid chloride in benzene solution (cf. Expt 5.96), and the resulting aclymalonic ester is then heated to 200 °C with an arylsulphonic acid to effect the decarbethoxylation step. An illustrative example is the preparation of ethyl 3-oxopentanoate (ethyl propionyl-acetate, Expt 5.177). 

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