反应详情

A solution of 4-(1,4-dioxa-8-aza-spiro[4.5]dec-8-yl)-benzaldehyde (2.47, 10 mmol) (Taylor, E. C., Skotnicki, J. S. Synthesis, 1981, 606) and diethyl malonate (2.0 g, 12.5 mmol) in toluene (100 mL) containing a catalytic quantity of piperidineum acetate was refluxed for 18 hours. After cooling to room temperature the solution was washed with water, dried over sodium sulfate and concentrated. Purification by column chromatography on silica gel using ethyl acetate/hexanes as the eluent gave the title compound as a yellowish gum; 1H NMR (300 MHz, CDCl3) δ 1.28 (t, J=7.1 Hz, 3H), 1.29 (t, J=7.1 Hz, 3H), 1.79 (t, J=5.8 Hz, 4H), 3.46 (t, J=5.8 Hz, 4H), 4.27 (q, J=7.1 Hz, 2H), 4.31 (q, J=7.1 Hz, 2H), 6.85 (d, J=8.9 Hz, 2H), 7.33 (d, J=8.9 Hz, 2H), 7.61 (s, 1H); MS (ES) m/z: 390.0 (MH+); HRMS Calcd. for C21H27NO6 (MH+): 390.1911. Found: 390.1910.

1. temperaturewas refluxed for 18 hours
2. washwas washed with water
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated
5. customPurification by column chromatography on silica gel