反应 #657325

反应方程式

3-Bromo-2-phenylpyrazolo[1,5-a]pyrimidine

tert-butyl [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]carbamate

Tert-butyl [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]carbamate

sodium carbonate

→

4-(2-phenylpyrazolo[1,5-a]pyrimidin-3-yl)pyridin-2-amine

收率 45.8%

溶剂

1,4-dioxan

water

反应条件

后处理

1. 1
   其他The reaction mixture is flushed with argon for 5 mins
2. 2
   其他sealed
3. 3
   温度the mixture is heated for 2 h at 120° C
4. 4
   萃取extracted with ethyl acetate (3×50 mL)
5. 5
   干燥The organic layer is dried over anhydrous magnesium sulphate
6. 6
   过滤filtered
7. 7
   浓缩concentrated under reduced pressure
8. 8
   其他The crude material is purified by column chromatography

实验过程

3-Bromo-2-phenylpyrazolo[1,5-a]pyrimidine (1.0 g, 3.65 mmol) and tert-butyl [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]carbamate (1.29 g, 4.01 mmol, 1.1 eq) are dissolved in 10 mL 1,4-dioxan. To this mixture bis(tricyclohexylphosphine)palladium(II)-dichloride (269 mg, 0.37 mmol, 0.1 eq) and 9.1 mL sodium carbonate solution (2 molar) are added. The reaction mixture is flushed with argon for 5 mins and then sealed. Next the mixture is heated for 90 min at 120° C. in the microwave (Biotage). Tert-butyl [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]carbamate (214 mg, 1.4 mmol, 0.37 eq) and bis(tricyclohexylphosphine)palladium(II)-dichloride (269 mg, 0.37 mmol, 0.1 eq) are then added and the mixture is heated for 2 h at 120° C. The reaction mixture is then poured in water and extracted with ethyl acetate (3×50 mL). The organic layer is dried over anhydrous magnesium sulphate, filtered and concentrated under reduced pressure. The crude material is purified by column chromatography using silica gel in heptane and ethyl acetate (1:0 to 1:1) as eluent and 0.48 g (44%) of 4-(2-phenylpyrazolo[1,5-a]pyrimidin-3-yl)pyridin-2-amine are obtained as a white solid.

来源