Reaktion #538280

Reaktionsgleichung

2-(2,4-difluorophenyl)cyclopentanone

carbonisocyanatidic chloride

toluene

→

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

Ausbeute 36.4%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed with an aqueous solution of sodium bicarbonate
2. 2
   SonstigeThe organic layer was separated
3. 3
   Extraktionthe aqueous layer was extracted with ethyl acetate
4. 4
   TrocknenThe combined organic extracts were dried over anhydrous magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   SonstigeThe solvent was removed in vacuum
7. 7
   Sonstigethe residue was purified by column chromatography on silica gel

Vorschrift

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).

Quelle