反应详情

Sodium hydride (16.5 9, content: 62.4%) was suspended in N,N-dimethylformamide (500 ml). 0-nitrophenol (60 g) dissolved in N,N-dimethylformamide (100 ml) was added dropwise into the mixture with stirring in ice-bath over about 20 mins. The mixture was stirred for 1 hr. at a room temperature. 4-bromobutanoic acid ethyl ester (84.2 g) dissolved in N,N-dimethylformamide (200 ml) was added to the mixture. The solution was stirred for 15 hrs at about 70° C. N,N-dimethylformamide was evaporated in vacuo. Ethyl acetate (800 ml) was added to the residue. The mixture was washed with a water and a saturated brine, dried over magnesium sulfate and evaporated. The residue was purified by column chromatography on silica gel (n-hexane: ethyl acetate =5:1→3:1) to give the title compound (77.3 g) having the following physical data:

1. additionwas added dropwise into the mixture
2. stirringThe mixture was stirred for 1 hr
3. customat a room temperature
4. additionwas added to the mixture
5. stirringThe solution was stirred for 15 hrs at about 70° C
6. customN,N-dimethylformamide was evaporated in vacuo
7. additionEthyl acetate (800 ml) was added to the residue
8. washThe mixture was washed with a water
9. dry with materiala saturated brine, dried over magnesium sulfate
10. customevaporated
11. customThe residue was purified by column chromatography on silica gel (n-hexane: ethyl acetate =5:1→3:1)