反应详情

A solution of 4-benzyloxyphenol (4.2 g) in dimethyl formamide (50 ml) was treated with sodium hydride (840 mg of a 60% dispersion), and the mixture stirred until evolution of gas ceased. There was then added ethyl 3-bromobutyrate (2.9 ml), and the solution stirred overnight. It was then poured into water (300 ml) and the mixture extracted with ether (3×50 ml). The combined extracts were washed with water (3×) and brine, dried (MgSO4) and evaporated to give a crude product as a brown oil (6 g). This was purified by chromatography on silica, eluting with hexane containing increasing amounts of ethyl acetate to give ethyl 3-(4-benzyloxyphenoxy)butyrate as a colourless crystalline solid (4.5 g) NMR (d6DMSO) : δ 1.25 (3H,t); 1.8-2.0 (2H,m); 2.45 (2H,t); 3.9 (2H,t); 4.1 (2H,q); 5.0 (2H,s); 6.8-7.0 (4H,m); 7.4 (5H,m); m/e 314 (M+H)+.

1. extractionthe mixture extracted with ether (3×50 ml)
2. washThe combined extracts were washed with water (3×) and brine
3. dry with materialdried (MgSO4)
4. customevaporated
5. customto give a crude product as a brown oil (6 g)
6. customThis was purified by chromatography on silica
7. washeluting with hexane containing
8. temperatureincreasing amounts of ethyl acetate