反应 #657315

反应方程式

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

2-isopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

2-(4-fluorophenyl)-7-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine

收率 44.0%

溶剂

THF

THF

反应条件

后处理

1. 1
   workup.STIRRINGthe reaction mixture is stirred for 2 hours at −78° C
2. 2
   其他Then the reaction mixture is quenched by the addition of an aqueous solution of NH4Cl
3. 3
   萃取is extracted with EtOAc
4. 4
   洗涤The combined organic phases are washed with water and brine
5. 5
   干燥dried over Na2SO4
6. 6
   浓缩concentrated in vacuo
7. 7
   其他The crude is purified by silica gel chromatography (eluent cyclohexane/ethyl acetate)

实验过程

To a solution of 3-bromo-2-(4-fluorophenyl)-7-methyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine (1.5 g, 4.82 mmol, 1 eq) in THF (40 ml) is added a solution of n-Buli (3.314 ml, 1.6 M, 5.30 mmol, 1.1 eq) dropwise at −78° C. After 20 min of stirring, a solution of 1.23 g of 2-isopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.23 mmol, 1.1 eq) in THF is added dropwise and the reaction mixture is stirred for 2 hours at −78° C. Then the reaction mixture is quenched by the addition of an aqueous solution of NH4Cl and is extracted with EtOAc. The combined organic phases are washed with water and brine, dried over Na2SO4 and concentrated in vacuo. The crude is purified by silica gel chromatography (eluent cyclohexane/ethyl acetate). 760 mg (42%) of 2-(4-fluorophenyl)-7-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine are obtained.

来源