Clofibrate → Clofibric Acid

関与物質

反応手順

To a solution of 2-(4-Chloro-phenoxy)-2-methyl-propionic acid ethyl ester (6 g, 24.79 mmol) in THF (20 ml) was added a solution of LiOH (3 g, 74.38 mmol) in H20 (4 ml). The resulting solution was stirred at room temperature for 12 hours. After evaporation of the solvent, the residue was diluted with ethyl acetate (100 ml); cool to 0° C., acidified with 1N HCl (PH˜3-4). The organic phase were washed with, brine (20 ml) and dried over Na2SO4. After evaporation, the residue was purified by flash chromatography (1:1 hexanes/EtOAc) to give 2-(4-Chloro-phenoxy)-2-methyl-propionic acid (1.1 g, 20%). 1H NMR (400 MHz, CDCl3): δ 1.60 (s, 6H), 6.85 (d, J=8.7 Hz, 2H), 7.22 (d, J=8.7 Hz, 2H). MS (EI) m/z: 215.5 (M+1).

情報源と証拠