反应详情

A solution of 4-bromo-1H-pyrazole (3.42 g, 23.43) and 3-methyl-2-butenoic acid ethyl ester (1 g, 7.81 mmol) in DMF (50 mL) was treated with cesium carbonate (10.1 g, 31.07) and allowed to stir for 3 hours at room temperature. The reaction mixture was diluted with water (30 mL) and extracted with EtOAc (3×30 mL). The combined extracts were dried over sodium sulfate and concentrated to afford the desired product, 1.1 g (51%) yield. 1H NMR (300 MHz, CDCl3) δ 7.51 (s, 1H), 7.45 (s, 1H), 3.98-4.05 (m, 2H), 2.82 (s, 2H), 1.62 (s, 6H), 1.18-1.10 (t, 3H).

1. extractionextracted with EtOAc (3×30 mL)
2. dry with materialThe combined extracts were dried over sodium sulfate
3. concentrationconcentrated