反应详情

To a solution of 2-tert-butylindoline (9.7 g) in H2SO4 (98%, 80 mL) was slowly added KNO3 (5.6 g, 56 mmol) at 0° C. After addition, the reaction mixture was stirred at room temperature for 1 h. The mixture was carefully poured into cracked ice, basified with Na2CO3 to pH 8 and extracted with ethyl acetate. The combined extracts were washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by column chromatography to give 2-tert-butyl-6-nitroindoline (4.0 g, 31% over two steps). 1H NMR (300 MHz, CDCl3) δ 7.52 (dd, J=1.8, 8.1 Hz, 1H), 7.30 (s, 1H), 7.08 (d, J=7.8 Hz, 1H), 3.76 (t, J=9.6 Hz, 1H), 2.98-3.07 (m, 1H), 2.82-2.91 (m, 1H), 0.91 (s, 9H).

1. customat 0° C
2. additionAfter addition
3. additionThe mixture was carefully poured into cracked ice
4. extractionextracted with ethyl acetate
5. washThe combined extracts were washed with brine
6. dry with materialdried over anhydrous Na2SO4
7. concentrationconcentrated under vacuum
8. customThe residue was purified by column chromatography