反应详情

温度

120 °C

A mixture of 2-(2,4-difluorophenyl)cyclopentanone (1.014 g, 5.17 mmol) and 50% wt. carbonisocyanatidic chloride solution in toluene (1.963 g, 9.30 mmol) was heated at 58° C. for 1 h and at 120° C. for 3 h. The reaction mixture was dissolved in ethyl acetate and washed with an aqueous solution of sodium bicarbonate. The organic layer was separated and the aqueous layer was extracted with ethyl acetate. The combined organic extracts were dried over anhydrous magnesium sulfate and filtered. The solvent was removed in vacuum and the residue was purified by column chromatography on silica gel to give 7-(2,4-difluorophenyl)-6,7-dihydrocyclopenta[e][1,3]oxazine-2,4(3H,5H)-dione (499.3 mg, 1.883 mmol, 36.4% yield) as brown solid. LC-MS (M+H)+=266.2. 1H NMR (500 MHz, CDCl3) δ ppm 8.19-8.64 (1H, m), 7.10 (1H, td, J=8.5, 6.3 Hz), 6.78-6.92 (2H, m), 4.36-4.49 (1H, m), 2.79-2.92 (1H, m), 2.59-2.78 (2H, m), 2.08 (1H, ddd, J=9.3, 6.9, 6.7 Hz).

1. washwashed with an aqueous solution of sodium bicarbonate
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with ethyl acetate
4. dry with materialThe combined organic extracts were dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. customThe solvent was removed in vacuum
7. customthe residue was purified by column chromatography on silica gel