反応 #657316

反応方程式

sodium carbonate

3-bromo-2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

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

→

4-(2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-3-yl)pyridin-2-amine

溶媒

1,4-dioxan

反応条件

後処理

1. 1
   その他The reaction mixture is flushed with argon for 5 mins
2. 2
   その他sealed
3. 3
   その他all crude reaction mixtures
4. 4
   温度After cooling
5. 5
   ろ過insoluble components are filtered off over Celite
6. 6
   洗浄the residue washed with 1,4-dioxan
7. 7
   その他The organic phase is evaporated
8. 8
   その他the crude product purified by column chromatography over silica gel
9. 9
   その他After evaporation of the solvents 2.10 g (41%) of 4-(2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-3-yl)pyridin-2-amine
10. 10
    その他are obtained as a colourless solid

実験手順

3-bromo-2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine (700 mg, 2.25 mmol) and tert-butyl [4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]carbamate (792 mg, 2.47 mmol, 1.1 eq) are dissolved in 10 mL 1,4-dioxan. To this mixture Bis(tricyclohexylphosphine)palladium(II)-dichloride (166 mg, 0.22 mmol, 0.1 eq) and 5.4 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 12 mins at 150° C. in the microwave (Biotage). The procedure is repeated 7× using the same scale and all crude reaction mixtures are combined thereafter. After cooling, insoluble components are filtered off over Celite and the residue washed with 1,4-dioxan. The organic phase is evaporated and the crude product purified by column chromatography over silica gel using dichloromethane/methanole as eluent. After evaporation of the solvents 2.10 g (41%) of 4-(2-phenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-3-yl)pyridin-2-amine are obtained as a colourless solid.

出典