Iodine → (E)-3-(4-Methoxybenzenesulfonyl)-2-propylacrylic acid

Beteiligte Stoffe

Reaktionsschritte

Sodium 4-methoxyphenylsulfinate (10.0 g, 51.49 mmol) was dissolved in water (50 ml). This solution was shaken with iodine (8.7 g, 34.29 mmol) in dichloromethane (60 ml). The dichloromethane layer turned from deep pink to orange. The dichloromethane layer was dried over magnesium sulfate and filtered into a flask containing 2-propylacrylic acid (2.0 g, 17.52 mmol). The solution was stirred overnight at room temperature and then cooled to 0° C. Triethylamine (7.3 ml, 51.49 mmol) was added and the solution was allowed to warm to room temperature over 2 hours. Sulphuric acid (2M, 50 ml) was added to quench the reaction. The organic phase was washed with 10% aqueous sodium bisulphite (50 ml), then extracted with sodium hydroxide (1 g) in water (50 ml). The aqueous layer was washed with MTBE (20 ml) and the acidifed with sulphuric acid (2M, 10 ml). The product was extracted into dichloromethane (2×30 ml) and the combined organic layers were washed with brine (20 ml), dried over magnesium sulfate, filtered and evaporated to give the title compound in 90% yield. This yellow solid was recrystallised from hot solvent (ethyl acetate:heptane:glacial acetic acid 1:1:0.2) to give the title compound as white crystals (4.02 g, 80%).

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