反应详情

20.8 g of 2,4-dimethoxycinnamic acid are dissolved in a hot mixture of 500 ml of methanol and 100 ml of ethyl acetate and, after addition of 1 g of catalyst (10% Pd/C), hydrogenated under atmospheric pressure. The uptake of hydrogen ought to be complete after 3 hours. If the hydrogenation is incomplete, more fresh catalyst is added. After the reaction is complete, the catalyst is removed, the solution is concentrated to about 200 ml, 20 ml of an approx. 2.4 M methanolic hydrochloric acid solution are added, and the mixture is left to stand at room temperature for 2 days. The esterification is then complete. The methanol is removed in vacuo, the residue is taken up in 200 ml of ethyl acetate, and the organic phase is washed with NaHCO3 solution and saturated NaCl solution (50 ml each 3 times), dried over Na2SO4 and concentrated.

1. additionmore fresh catalyst is added
2. customthe catalyst is removed
3. concentrationthe solution is concentrated to about 200 ml, 20 ml of an approx. 2.4 M methanolic hydrochloric acid solution
4. additionare added
5. waitthe mixture is left
6. customThe methanol is removed in vacuo
7. washthe organic phase is washed with NaHCO3 solution and saturated NaCl solution (50 ml each 3 times)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated