反応 #657311

反応方程式

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

K2CO3

butane-2,3-diyl dimethanesulfonate

→

6-(4-fluorophenyl)-2,3-dimethyl-2,3-dihydropyrazolo[5,1-b][1,3]oxazole

収率 71.8%

溶媒

DMF

water

反応条件

後処理

1. 1
   その他prepared
2. 2
   その他at room temperature
3. 3
   抽出extracted with ethyl acetate
4. 4
   乾燥The organic layer was dried over anhydrous sodium sulphate
5. 5
   濃縮concentrated
6. 6
   その他to get the crude product
7. 7
   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 (3 g, 16.8 mmol) in DMF (15 mL) was added K2CO3 (9.3 g, 67.4 mmol) and butane-2,3-diyl dimethanesulfonate (4.8 g, 18.5 mmol) (prepared as described in US2010/41748) at room temperature and then stirred for 16 h at 60° C. Thereafter, the reaction mixture was diluted with cold water and extracted with ethyl acetate. 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-(4-fluorophenyl)-2,3-dimethyl-2,3-dihydropyrazolo[5,1-b][1,3]oxazole (2.8 g, 71%) as yellow oil and a mixture of diastereoisomers.

出典