反应详情

Nitric acid (5 mL, 70%) was added slowly to a stirred solution of 2-methylindolizine 1 (see preparation of Example 1) (5 g, 38.2 mmol) in concentrated sulphuric acid (15 mL, 96%) at 0° C. After 5 minutes, the brown solution obtained was poured onto crushed ice. The orange precipitate formed was immediately isolated by filtration, washed with copious amounts of water and then dried under vacuum in the presence of P2O5 for a night to give 2-methyl-1-nitroindolizine 13 (3 g), m.p. 137-139° C. 1H NMR (DMSO-d6): δ 8.55 (dt, J=6.7, 1.0 Hz, 1H), 8.20 (d, J=9.1 Hz, 1H), 7.54-7.48 (m, 2H), 7.11 (dt, J=8.0, 1.2 Hz, 1H), 2.47 (d, J=1.0 Hz, 3H). 13C NMR (DMSO-d6): δ 132.2, 128.0, 127.7, 123.0, 122.8, 117.8, 115.0, 114.7, 12.4.

1. customthe brown solution obtained
2. additionwas poured
3. customonto crushed ice
4. customThe orange precipitate formed
5. customwas immediately isolated by filtration
6. washwashed with copious amounts of water
7. dry with materialdried under vacuum in the presence of P2O5 for a night