123-91-1

251565-89-6

142-82-5

251565-85-2

The general procedure for the synthesis of (S)-2-ethoxy-3-{4-[2-(4-methylsulfonylphenyl)ethoxy]phenyl}propionic acid from 1,4-dioxane, the compound (CAS: 251565-89-6) and n-heptane was as follows: (S)-2-ethoxy-3-{4-[2-{4-methanesulfonylphenyl)ethoxy]phenyl}propionic acid was synthesized by mixing (S)-2-ethoxy-N-(2-hydroxy(R)-1-phenylethyl)-3-[4-[2-{4-methanesulfonyloxy phenyl}ethoxy)phenyl]propionamide (4.49 g, 8.59 mmol), concentrated sulfuric acid (12.5 mL), 1,4-dioxane (50 mL), and water (50 mL) were stirred at 80 °C for 6 hours. After the reaction was completed, it was cooled to room temperature, water (100 mL) was added and the product was extracted with dichloromethane (2 x 100 mL). The organic phases were combined, washed with brine (60 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The product was purified by silica gel column chromatography using gradient elution with n-heptane:ethyl acetate:acetic acid (10:10:1, v/v/v) as eluent, and finally distilled by azeotropic distillation through toluene to afford (S)-2-ethoxy-3-[4-(2-{4-methanesulfonyloxyphenyl}ethoxy)phenyl]propanoic acid (2.78 g, 79% yield). The product was structurally confirmed by 1H-NMR (600 MHz, DMSO-d6) and 13C-NMR (150 MHz, DMSO-d6).