反应详情

The reaction mixture is stirred for 1/2 hour at the same temperature, a solution of 179 g of hexamethylphosphoramide in 200 ml of tetrahydrofuran is added and stirring is continued for 1/2 hour at -78°. At the same temperature a solution of 125 g of methyl N,N-dimethylaminopropionate in 200 ml of tetrahydrofuran is then added dropwise and stirring is continued for 20 minutes. A solution of 171 g of benzyl bromide in 300 ml of tetrahydrofuran is then added, again at -78°. The solution is stirred at this temperature for 2 hours and then quenched, first with 250 ml of saturated aqueous ammonium chloride and then 250 ml of saturated aqueous sodium chloride solution. To this is added 1500 ml of ether. The layers are separated and the aqueous layer is extracted with 4×200 ml of ether. The ether extract is dried over magnesium sulfate and evaporated to dryness. The resulting oil is redissolved in 300 ml of ether, the ether solution is washed with 100 ml of water and the aqueous layer is reextracted with 3×100 ml ether. The combined ether solutions are dried over magnesium sulfate and evaporated to dryness to yield an oil which is purified by fractional distillation to yield pure methyl 2-benzyl-3-dimethylaminopropionate, b.p. 104°/0.2-0.4 mm Hg.

1. stirringstirring
2. waitis continued for 1/2 hour at -78°
3. stirringstirring
4. waitis continued for 20 minutes
5. stirringThe solution is stirred at this temperature for 2 hours
6. customquenched, first with 250 ml of saturated aqueous ammonium chloride
7. additionTo this is added 1500 ml of ether
8. customThe layers are separated
9. extractionthe aqueous layer is extracted with 4×200 ml of ether
10. extractionThe ether extract
11. dry with materialis dried over magnesium sulfate
12. customevaporated to dryness
13. dissolutionThe resulting oil is redissolved in 300 ml of ether
14. washthe ether solution is washed with 100 ml of water
15. dry with materialThe combined ether solutions are dried over magnesium sulfate
16. customevaporated to dryness
17. customto yield an oil which
18. distillationis purified by fractional distillation