Water → p-Toluenesulfonic acid

Participants

Reaction Steps

Starting from 241.5 g of 4-toluenesulphonic acid hydrate, the water was eliminated using benzene. When water was no longer separated off, the benzene was distilled off. Any remaining benzene was expelled in a stream of nitrogen. 189.9 g (1.10 mol) of 4-toluenesulphonic acid were obtained. Then, chlorine was passed in at 60° C. until the increase in weight of the batch corresponded to the theoretically expected increase (39 g). After remaining chlorine and hydrogen chloride had been expelled in a stream of nitrogen, the effective increase in weight of the batch was 37.4 g (1.06 mol of chlorine). High-performance liquid chromatography analysis (HPLC) showed a content of 88.3% (88.3% of the theoretical yield) of 2-chloro-4-toluenesulphonic acid besides 1.72% (1.72% of the theoretical yield) of 3-chloro-4-toluenesulphonic acid and 1.3% (1.56% of the sulphonic acid employed) of 4-toluenesulphonic acid.

Provenance & Evidence