反应详情

温度

125 °C

To a mixture of 4-methoxy-2-nitrobenzaldehyde (20 g, 0.11 mol) and malonic acid (28.8 g, 0.28 mol) in pyridine (200 mL) is added piperidine (1 mL, catalytic amount) and the mixture is refluxed at 125° C. under nitrogen for 12 h. After cooling to room temperature, the solvent is removed under reduced pressure and the residue is acidified with 1.5 N HCl. The product is extracted with EtOAc and the organic layer is washed with water and brine then dried over Na2SO4. The solvent is removed under reduced pressure to afford 16 g (65%) of the title compound as a pale brown solid. 1H NMR (DMSO-d6, 400 MHz) δ 12.59 (bs, 1H), 7.91-7.93 (m, 1H), 7.68-7.72 (m, 1H), 7.56 (s, 1H), 7.31-7.33 (m, 1H), 7.46-7.50 (m, 1H), 3.87 (s, 3H).

1. temperatureAfter cooling to room temperature
2. customthe solvent is removed under reduced pressure
3. extractionThe product is extracted with EtOAc
4. washthe organic layer is washed with water and brine
5. dry with materialthen dried over Na2SO4
6. customThe solvent is removed under reduced pressure