反应详情

To a suspension of 1,3-dimethoxy-5-methyl-benzene (5.10 g, 33.55 mmol) and succinic anhydride (3.69 g, 36.91 mmol) in nitrobenzene (100 mL) was added AlCl3 (8.9 g, 67.10 mmol). The reaction mixture was stirred at room temperature for 16 hours then carefully poured into aqueous NaOH. The pH was adjusted to 10 with solid NaOH and the aqueous solution washed with dichloromethane. The pH of the aqueous solution was adjusted to 3 with concentrated HCl and extracted with EtOAc. The organic extracts were dried and concentrated in vacuo. The residue was triturated dichloromethane to give 4-(2,4-dimethoxy-6-methyl-phenyl)-4-oxo-butyric acid as a pale yellow solid (3.7 g, 43%). 1H NMR (400 MHz, MeOD-d4) δ 6.44 (s, 1H), 6.40 (s, 1H), 3.80 (s, 3H), 3.78 (s, 3H), 3.03 (t, J=8.1 Hz, 2H), 2.60 (t, J=8.1 Hz, 2H), 2.19 (s, 3H).

1. washthe aqueous solution washed with dichloromethane
2. extractionextracted with EtOAc
3. customThe organic extracts were dried
4. concentrationconcentrated in vacuo
5. customThe residue was triturated dichloromethane