反应详情

A solution of 22.6g (0.11 mole) of sodium saccharin and 15g (0.1 mole) of tert-butyl α-chloroacetate in 150 ml of dimethylformamide is heated on a steam bath for 1 hour, allowed to stir at room temperature for 16 hours and poured into ice-water. The solution is dried over magnesium sulfate and the solvent is evaporated to give 24.9g of tert-butyl N-saccharinylacetate, m.p. 130°-132.5° C. This is refluxed with 300 ml of benzene and 1.4g (0.01 mole) of p-toluenesulfonic acid monohydrate to cause quantitative precipitation of 2-carboxymethylsaccharin, m.p. 212°-215° C. The completion of the reaction is established by passing a slow stream of nitrogen through the reaction mixture and into a solution of bromine in carbon tetrachloride. Failure to decolorize the bromine indicates that no more isobutylene is being evolved.

1. dry with materialThe solution is dried over magnesium sulfate
2. customthe solvent is evaporated