Chlorosulfonic acid → 2-Tosylethyl 2-(4-(chlorosulfonyl)phenoxy)acetate

Participants

Reaction Steps

To an ice-bath cooled mixture of phenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 3, 3.0 g) and 1 mL of CH2Cl2 was added drop-wise 3.0 mL of chlorosulfonic acid (5.2 g, 5.0 eq). After the addition of the chlorosulfonic acid was complete the ice bath was removed. The mixture was continued to stir at room temperature for 3 h. Thereafter the thick syrupy mixture was poured onto the crushed ice with vigorous stirring. White precipitates were collected by filtration, were washed with methanol and cold benzene, and dried overnight under high vacuum to yield 3.4 g (87%) of Intermediate 4 as white powder.

Provenance & Evidence