反応 #657309

反応方程式

3-(4-fluorophenyl)-1H-pyrazol-5-ol

K2CO3

2,2-difluoropropane-1,3-diyl dimethanesulfonate

→

6,6-difluoro-2-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

収率 56.0%

溶媒

DMF

water

反応条件

後処理

1. 1
   抽出extracted with diethyl ether
2. 2
   乾燥The organic layer was dried over anhydrous sodium sulphate
3. 3
   濃縮concentrated
4. 4
   その他to get the crude product
5. 5
   その他Purification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether)

実験手順

To a solution of 3-(4-fluorophenyl)-1H-pyrazol-5-ol (4 g, 22.47 mmol) in DMF (30 mL) was added K2CO3 (12.4 g, 89.88 mmol) and 2,2-difluoropropane-1,3-diyl dimethanesulfonate (9 g, 33.7 mmol) at room temperature and then stirred for 16 h at 60° C. The progress of the reaction was monitored by TLC. Thereafter, the reaction mixture was diluted with cold water and extracted with diethyl ether. The organic layer was dried over anhydrous sodium sulphate and concentrated to get the crude product. Purification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether) yielded 6,6-difluoro-2-(4-fluorophenyl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine (3.2 g, 56%) as an off-white solid.

出典