Toluene → {2-[2-(Toluene-4-sulfonyl)-ethoxycarbonylmethoxy]-phenoxy}-acetic acid 2-(toluene-4-sulfonyl)ethyl ester

Participants

Reaction Steps

1,2-Phenylenedioxydiacetic acid (available from Aldrich, 5 g, 22.1 mmole) and 2-(p-tolylsulfonyl)ethanol (available from Aldrich, 8.8 g, 44.2 mmole) were added to toluene (100 mL). Catalytic amounts of p-toluenesulfonic acid hydrate (0.5 g) were added and the reaction mixture was refluxed with removal of water, using Dean-Stark trap. After 6 hr of reflux, the toluene was distilled off. The residual material was dissolved in dichloromethane (250 mL) and washed with water (200 mL), and 6 N sodium bicarbonate solution (150 mL). The dichloromethane layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to yield 13 g (99%) of {2-[2-(toluene-4-sulfonyl)-ethoxycarbonylmethoxy]-phenoxy}-acetic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 37)

Provenance & Evidence