反应详情

温度

90 °C

A mixture of trans-4-methoxycinnamic acid (18 g, 101 mmol) and concentrated H2SO4 (0.5 ml) in absolute EtOH (100 ml) was refluxed at 90° C. (bath temperature) for 16 h. After the excess EtOH was removed by a rotary evaporator, the residue was treated with H2O (100 ml), and the resulting mixture was extracted with ether (3×120 ml). The combined extracts were washed with 1N aq. NaOH (2×50 ml), H2O (80 ml) and brine (80 ml), and dried (anhydrous Na2SO4). The solvent was evaporated to dryness to give ethyl trans-4-methoxycinnamate (20 g, 96% yield) as light yellow oil, which was pure enough for the next step.

1. customAfter the excess EtOH was removed by a rotary evaporator
2. additionthe residue was treated with H2O (100 ml)
3. extractionthe resulting mixture was extracted with ether (3×120 ml)
4. washThe combined extracts were washed with 1N aq. NaOH (2×50 ml), H2O (80 ml) and brine (80 ml)
5. dry with materialdried (anhydrous Na2SO4)
6. customThe solvent was evaporated to dryness