反应详情

A solution of (2S)-3-(4-hydroxyphenyl)-2-methoxypropanoic acid (35 g) in 140 ml of ethanol was mixed with 5.66 ml of concentrated sulfuric acid and stirred at room temperature until complete as indicated by HPLC. The ethanol was removed via vacuum distillation (55° C./28″Hg) and 110 ml of water was added. The pH was adjusted to about 7 to 8 with sodium bicarbonate, and the mixture was extracted with add 50 ml ethyl acetate (3×50 ml). The organic layers were combined, washed with 50 ml 20% NaCl solution, dried with 15 g of magnesium sulfate, and concentrate product to afford ethyl (2S)-2-methoxy-3-(4-hydorxyphenyl)propanoate as an oil. 1H-NMR (CDCl3): 7.1 (d, 2H); 6.7(d, 2H); 4.2(m, 2H); 3.9(m, 1H); 3.6(s, 3H); 2.95(m, 2H); 1.25(t, 3H). MS (ES): 223.2 (M−1).

1. customThe ethanol was removed via vacuum distillation (55° C./28″Hg) and 110 ml of water
2. additionwas added
3. extractionthe mixture was extracted
4. additionwith add 50 ml ethyl acetate (3×50 ml)
5. washwashed with 50 ml 20% NaCl solution
6. dry with materialdried with 15 g of magnesium sulfate
7. concentrationconcentrate product