反应详情

温度

-70 °C

Ethylpropionate (10.2 g; 0.1 mol) was added dropwise to a solution of lithium-di-isopropylamide (0.1 mol) which was obtained by mixing at 0° C. under nitrogen 10 g di-isopropylamine in 100 ml dry tetrahydrofuran with n-butyllithium in hexane (45.5 ml; 2.2 M). After the addition of ethylpropionate (which was carried out at a temperature of -78° C.) the mixture was stirred at -78° C. for 10 minutes, whereafter a solution of 1,3-dimethoxybenzylbromide (23.0 g; 0.1 mol) in dry hexamethylphosphoric acid triamide (9 g) was added dropwise. The mixture was stirred at -70° C. for 10 minutes and then heated to 0° C. Water was added and the mixture was extracted with ether. The ether-extract was dried on Na2SO4 and the solvent was evaporated. Destillation of the residue in vacuum gave 19.4 g pure product (77% yield), boiling point 150°-155° C./0.2 mm.

1. customwas obtained
2. customwas carried out at a temperature of -78° C.
3. additionwas added dropwise
4. temperatureheated to 0° C
5. extractionthe mixture was extracted with ether
6. extractionThe ether-extract
7. customwas dried on Na2SO4
8. customthe solvent was evaporated