Реакция #538280

Уравнение реакции

2-(2,4-difluorophenyl)cyclopentanone

carbonisocyanatidic chloride

toluene

→

7-(2,4-difluorophenyl)-6,7-dihydrocyclopenta[e][1,3]oxazine-2,4(3H,5H)-dione

Выход 36.4%

Растворители

ethyl acetate

Условия реакции

Обработка

1. 1
   Промывкаwashed with an aqueous solution of sodium bicarbonate
2. 2
   ДругоеThe organic layer was separated
3. 3
   Экстракцияthe aqueous layer was extracted with ethyl acetate
4. 4
   СушкаThe combined organic extracts were dried over anhydrous magnesium sulfate
5. 5
   Фильтрацияfiltered
6. 6
   ДругоеThe solvent was removed in vacuum
7. 7
   Другоеthe residue was purified by column chromatography on silica gel

Методика

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).

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