反应 #657311

反应方程式

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

收率 71.8%

溶剂

DMF

water

反应条件

后处理

1. 1
   其他prepared
2. 2
   其他at room temperature
3. 3
   萃取extracted with ethyl acetate
4. 4
   干燥The organic layer was dried over anhydrous sodium sulphate
5. 5
   浓缩concentrated
6. 6
   其他to get the crude product
7. 7
   其他Purification by column chromatography over silica gel (eluent 5-10% ethyl acetate in petrol ether)

实验过程

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.

来源