反应详情

To a solution of ethyl benzoylacetate (10.00 g, 52.0 mmol., 1 eq) and m-anisidine (7.05 g, 57.2 mmol., 1.1 eq) in toluene (85 mL) was added 4M HCl in dioxane (0.520 mL, 2.08 mmol., 0.04 eq) dropwise. The reaction mixture was refluxed for 15 hours while water was collected in a Dean-Stark apparatus. The reaction mixture was left to cool to ambient temperature and the solvent removed under vacuum. The residue was suspended in diphenyl ether (28 mL) and the mixture was heated for 2 h at 240° C. The reaction mixture was then left to cool to ambient temperature and dichloromethane (55 mL) was added, leading to the precipitation of a yellow solid. Stirring was continued at ambient temperature for a further 30 min and the solid collected by filtration, rinsing the cake with a small amount of dichloromethane. The solid was transferred to a 100 mL round bottom flask and stirred with dichloromethane (50 mL) for another 45 min at ambient temperature. After filtration and drying under high vacuum, 2.85 g (22%) of the title compound was isolated as a pale yellow solid. 1H NMR (250 MHz, DMSO-d6) δ ppm 11.54 (s, 1 H), 7.99 (d, J=8.91 Hz, 1 H), 7.73-7.90 (m, 2 H), 7.48-7.64 (m, 3 H), 7.20 (d, J=2.32 Hz, 1 H), 6.94 (dd, J=2.34, 8.97 Hz, 1 H), 6.26 (s, 1 H), 3.86 (s, 3 H). LC-MS: purity 98% (UV), tR 1.52 min, m/z [M+1]+ 252.10.

1. customwas collected in a Dean-Stark apparatus
2. waitThe reaction mixture was left
3. customthe solvent removed under vacuum
4. temperaturethe mixture was heated for 2 h at 240° C
5. waitThe reaction mixture was then left
6. temperatureto cool to ambient temperature
7. additiondichloromethane (55 mL) was added
8. customleading to the precipitation of a yellow solid
9. filtrationthe solid collected by filtration
10. washrinsing the cake with a small amount of dichloromethane
11. customThe solid was transferred to a 100 mL round bottom flask
12. stirringstirred with dichloromethane (50 mL) for another 45 min at ambient temperature
13. filtrationAfter filtration
14. customdrying under high vacuum