Sulfuric Acid → 2-Isopropylpyrazolo[1,5-a]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1-(2-Isopropyl-pyrazolo[1,5-a]pyridin-3-yl)-2-methyl-propan-1-one (30.0 g, 115 mmole), water (100 ml), and concentrated sulfuric acid (100 ml) were combined and stirred at 130° C. for 18 hours. The mixture was cooled to room temperature and poured into a solution of ice (400 g) and water (200 ml). The solution was neutralized with sodium hydroxide solution and extracted with chloroform. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. The oil was purified by vacuum distillation to give 14.9 g (81%) of 2-isopropyl-pyrazolo[1,5-a]pyridine. 1H-NMR (250 MHz, DMSO-d6) δ 8.37 (d, J=7.3 Hz, 1H), 7.41 (d, J=9.0 Hz, 1H), 7.00 (t, J=7.3 Hz, 1H), 6.66 (t, J=7.5 Hz, 1H), 6.28 (s, 1H), 3.16 (sept, J=7.0 Hz, 1H), 1.35 (d, J=6.8 Hz, 6H).

Herkunft & Nachweise