反应详情

Ex-20B: A solution of 4-fluoro-3-(thiophen-2-yl)-benzaldehyde (1.11 g, 5.38 mmol) from Ex-20A and pyrrolidine (13.0 g, 183.0 mmol) in dimethylformamide (30 mL) was treated with solid K2CO3 (1.7 g, 12.3 mmol), and the resulting mixture was stirred at reflux for 1 week. Upon cooling to room temperature, the reaction was poured into water (100 mL) and extracted with ethyl acetate (2×100 mL). The organic phase was dried over magnesium sulfate, and the solvent was removed under reduced pressure. Silica gel chromatography (hexane/ethyl acetate, 2:1) gave 400 mg (29%) of the desired 4-pyrrolidin-1-yl-3-(thiophen-2-yl)-benzaldehyde product as a yellow oil. 1H-NMR (300 MHz, CDCl3) δ 9.75 (s, 1H), 7.71–7.74 (m, 2H), 7.30 (dd, 1H, J=5.1 and 1.6 Hz), 7.02 (dd, 1H, J=5.1 and 3.7 Hz), 6.96 (m, 1H), 6.81 (d, 1H, J=10.1 Hz), 3.15 (m, 4H), 1.84 (m, 4H).

1. temperatureat reflux for 1 week
2. extractionextracted with ethyl acetate (2×100 mL)
3. dry with materialThe organic phase was dried over magnesium sulfate
4. customthe solvent was removed under reduced pressure