反应 #3746382
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openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US08754230B2
反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: To a solution of 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum's acid, 8.0 g, 56 mmol) dissolved in anhydrous methylene chloride (100 mL) and pyridine (11 mL), at 0° C. under nitrogen atmosphere, was slowly added 2-(4-fluorophenyl)acetyl chloride (7.6 mL, 9.6 g, 56 mmol). The red solution was stirred at 0° C. for 1.5 h. The reaction mixture was treated with 1 N HCl (13 mL) and diluted with methylene chloride (200 mL). The layers were separated and the organic layer was washed with saturated aqueous sodium chloride, dried and concentrated in vacuo to give 5-(2-(4-fluorophenyl) acetyl)-2,2-dimethyl-1,3-dioxane-4,6-dione. The crude intermediate was suspended in absolute EtOH (150 mL) and the resulting mixture was refluxed for 4 hours. The solvent was then removed in vacuo and the residue was purified by flash column chromatography (SiO2, 230-400 mesh, 8:1 hexane-ethyl acetate gradient elution) to afford the desired product (4.6 g, 37%). 1H NMR (CDCl3) δ 7.23-7.15 (m, 2 H), 7.05-6.98 (m, 2 H), 4.18 (q, 2 H, J=7.0 Hz), 3.81 (s, 2 H), 3.46 (s, 2 H), 1.26 (t, 3 H, J=7.0 Hz); MS (ESI+) m/z 225 (M+H)+. at 0° C. The layers were separated the organic layer was washed with saturated aqueous sodium chloride dried concentrated in vacuo
来源 ID: ord-5b4787ec63004ee28ede82bb12e1bf2d