反应详情

A solution of 4-methoxypropiophenone (24 g, 140 mmol) in tetrahydrofuran (220 mL) was cooled to 0° C. Lithium diisopropylamide, (2M solution in THF) (126 mL, 248 mmol) was added dropwise and warmed to rt for 30 min. The reaction was cooled again to 0° C. and ethyl bromoacetate (18 mL, 161 mmol) was added dropwise and warmed to rt for 30 min and then quenched with aqueous 1M HCl acid at 0° C. The aqueous layer was extracted twice with methylene chloride and the combined organics were washed with brine, dried (Na2SO4), filtered, and concentrated to give 4-(4-methoxyphenyl)-3-methyl-4-oxobutyric acid ethyl ester (44 g), MS m/z 205 (M−45).

1. temperatureThe reaction was cooled again to 0° C.
2. temperaturewarmed to rt for 30 min
3. customquenched with aqueous 1M HCl acid at 0° C
4. extractionThe aqueous layer was extracted twice with methylene chloride
5. washthe combined organics were washed with brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated