反应详情

To a solution of 4,5-dihydro-N,N-dimethyl-5-phenyl-3-isoxazolecarboxamide (i.e. the product of Example 12, Step A) (17 g, 78.0 mmol) in a mixture of tetrahydrofuran (20 mL) and toluene (80 mL) was added methyl magnesium bromide (3.0 M solution in tetrahydrofuran, 28 mL, 84 mmol) over 1 h, while keeping the reaction temperature between −10 and −15° C. The reaction mixture was poured over a mixture of concentrated hydrochloric acid (20 g) and ice (80 g), and the organic phase was separated. The aqueous phase was extracted with ethyl acetate (100 mL), and the combined organic extracts were washed with brine (40 mL) and concentrated under reduced pressure to give 14.4 g of 1-(4,5-dihydro-5-phenyl-3-isoxazoyl)ethanone as a light yellow oil.

1. customthe reaction temperature between −10 and −15° C
2. customthe organic phase was separated
3. extractionThe aqueous phase was extracted with ethyl acetate (100 mL)
4. washthe combined organic extracts were washed with brine (40 mL)
5. concentrationconcentrated under reduced pressure