反应详情

To a cooling (0° C.) solution of 3-cyclopropyl-1H-pyrazole (1.5 g, 13.89 mmol) in concentrated H2SO4 (20 mL, 98%) was added concentrated HNO3 (20 mL, 65%) over 2 min. The reaction mixture was stirred over 1 hr at this temperature. It was then diluted with ice-water and extracted with EA (30 mL×4). The organic phase was combined and washed with saturated sodium bicarbonate (50 mL). It was dried over Na2SO4 and concentrated in vacuo to give a crude product (1.5 g, 70%). This crude product was pure enough to be delivered or used to the next step reaction. MS: [M+H]+154. 1H NMR (500 MHz, CDCl3) δ 0.97 (m, 2H), 1.22 (m, 2H), 2.66 (m, 1H), 8.20 (s, 1H), 8.38 (s, 1H).

1. extractionextracted with EA (30 mL×4)
2. washwashed with saturated sodium bicarbonate (50 mL)
3. dry with materialIt was dried over Na2SO4
4. concentrationconcentrated in vacuo