反应详情

A 100 ml round-bottom flask equipped with a Dean-Stark trap was charged with 50 ml benzene, ethyl 1-formyl-4-oxo-4H-quinolizine-3-carboxylate (8) (1.22 g, 5 mmol), acetic acid (5 g, 83 mmol), NH4OAc (5 g, 65 mmol), and diethyl malonate (2.3 g, 9 mmol). The reaction mixture was refluxed for 48 h. The reaction mixture was cooled to room temperature and washed three times with 50 ml water. The solvent was evaporated in vacuo and the crude product was purified by flash chromatography (ethyl acetate) to yield ethyl 1-(2,2-dicarboethoxyvinyl)-4-oxo-4H-quinolizine-3-carboxylate (12) as a yellow powder (1.58 g, 82%). M.p. 149-151° C. 1H NMR (δ, CDCl3): 1.31 (t, J=7 Hz, 3H), 1.36 (t, J=7 Hz, 3H), 1.42 (t, J=7 Hz, 3H), 4.34 (q, J=7 Hz, 2H), 4.36 (q, J=7 Hz, 2H), 4.41 (q, J=7 Hz, 2H), 7.34 (dd, J=7 Hz, J=7 Hz, 1H), 7.82 (dd, J=8 Hz, 1H), 7.96 (d, J=8 Hz, 1H), 8.05 (s, 1H), 8.60 (s, 1H), 9.50 (d, J=7 Hz). MS: m/z 387.1331; required for C20H21NO7: 387.1318.

1. customA 100 ml round-bottom flask equipped with a Dean-Stark trap
2. temperatureThe reaction mixture was refluxed for 48 h
3. washwashed three times with 50 ml water
4. customThe solvent was evaporated in vacuo
5. customthe crude product was purified by flash chromatography (ethyl acetate)