反应详情

A solution of 25.84 g (0.1072 mol) of dimethyl 2-(3-methoxy-4-methylbenzyl)malonate in 150 mL of MeOH was treated with a solution of 20 g (0.5 mol) of NaOH in 100 mL of H2O and heated at reflux overnight. The solution was concentrated under reduced pressure and the residue taken up in H2O and washed with Et2O. The solution was acidified to Congo Red end point with dilute HCl and the solution extracted with Et2O. The Et2O was washed with saturated NaCl and dried over MgSO4. Removal of the solvent under reduced pressure gave 25.6 g of an oil. This was taken up in 125 mL of dioxane and heated at reflux overnight. Removal of the solvent under reduced pressure gave 20.5 g of the crude product. Chromatography on silica gel, eluting with CHCl3/MeOH (98/2) gave 8.65 g (41.6% yield) of the product as a white solid, mp 80-82° C. The structure was confirmed by NMR and mass spectroscopy. MS m/z 195 (M+H+).

1. temperatureheated
2. temperatureat reflux overnight
3. concentrationThe solution was concentrated under reduced pressure
4. washwashed with Et2O
5. extractionthe solution extracted with Et2O
6. washThe Et2O was washed with saturated NaCl
7. dry with materialdried over MgSO4
8. customRemoval of the solvent under reduced pressure