反应详情

To fuming nitric acid (5 mL) cooled to 5° was added neat 4-bromoisopropylbenzene (1.0 g, 5.023 mmol) dropwise at such a rate that the reaction temperature remained below 10°. The reaction was stirred for 2 hours at 5-10°, quenched with ice (50 g), extracted with ethyl acetate (50 mL), and the organic extract was washed with water (2×25 mL) and brine (25 mL), then dried over magnesium sulfate filtered and concentrated by rotary evaporation. The residue was purified by silica gel flash chromatography eluting with 5:95 ethyl acetate/hexanes to afford the title compound as a light yellow solid (1.03 g, 4.22 mmol, 84%). 1H NMR (300 MHz, CHLOROFORM-D) δ ppm 1.27 (d, J=6.99 Hz, 6 H) 2.75-3.23 (m, 1 H) 7.29 (dd, J=8.82, 2.21 Hz, 1 H) 7.63 (d, J=8.09 Hz, 1 H) 7.69 (d, J=2.21 Hz, 1 H); MS (DCI) m/z 261/263 (M+NH4)−.

1. customremained below 10°
2. customquenched with ice (50 g)
3. extractionextracted with ethyl acetate (50 mL)
4. extractionthe organic extract
5. washwas washed with water (2×25 mL) and brine (25 mL)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated by rotary evaporation
9. customThe residue was purified by silica gel flash chromatography
10. washeluting with 5:95 ethyl acetate/hexanes