反应详情

To a solution of ethyl 4-benzyloxy-3-methoxyphenylacetate (32 g, 110 mmol), from Step 1, in ethanol (200 mL) and THF (20 mL) was added 200 mL of a 1M aqueous lithium hydroxide solution. The resulting mixture was stirred at ambient temperature for 4 hours and then 1M aqueous hydrochloric acid solution was added to precipitate the product. The solid was filtered, washed with water, taken up in diethyl ether, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give the title compound as a yellow solid. The solid was recrystallized from methylene chloride/petroleum ether (b.p. 30°-60° C.) to give 19 g (58% yield based on ethyl 4-hydroxy-3-methoxyphenylacetic acid) of the title compound as a white solid; 1H NMR (CDCl3) δ 3.57 (s, 2H), 3.88 (s, 3H), 5.14 (s, 2H), 6.74 (dd, 1H, J=8.0, 2.7 Hz), 6.82-6.85 (m, 2H), 7.28-7.45 (m, 5H).

1. customto precipitate the product
2. filtrationThe solid was filtered
3. washwashed with water
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure