反应详情

137 g of the above-obtained oil containing N-ethoxy-2,4-dibromobutyric acid amide were dissolved in 500 mL of benzene. To the resultant solution, 12 g of sodium hydride were gradually added while cooling the solution to 15° C. to 20° C. After the completion of the addition, ice was added to the resultant reaction solution to decompose excessive sodium hydride. The resultant solution was washed with a saturated saline, followed by drying the solution by magnesium sulfate. The solution was concentrated under a reduced pressure and purified by silica gel-acetone/benzene column chromatography to give 42 g (0.20 mol) of N-ethoxy-2-bromo-4-butyrolactam (with a yield of 37% from 2,4-dibromobutyric acid bromide).

1. temperaturewhile cooling the solution to 15° C. to 20° C
2. additionAfter the completion of the addition, ice
3. additionwas added to the resultant
4. customreaction solution
5. washThe resultant solution was washed with a saturated saline
6. dry with materialby drying the solution by magnesium sulfate
7. concentrationThe solution was concentrated under a reduced pressure
8. custompurified by silica gel-acetone/benzene column chromatography