تفاعل #657315

معادلة التفاعل

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

المردود 44.0%

المذيبات

THF

THF

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGthe reaction mixture is stirred for 2 hours at −78° C
2. 2
   أخرىThen the reaction mixture is quenched by the addition of an aqueous solution of NH4Cl
3. 3
   استخلاصis extracted with EtOAc
4. 4
   غسيلThe combined organic phases are washed with water and brine
5. 5
   تجفيفdried over Na2SO4
6. 6
   تركيزconcentrated in vacuo
7. 7
   أخرىThe crude is purified by silica gel chromatography (eluent cyclohexane/ethyl acetate)

الإجراء التجريبي

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.

المصدر