反应 #9472

反应方程式

ammonium chloride

3-bromo-5-(tert-butyldimethylsilanyloxymethyl)pyridine

triisopropyl borate

n-Butyllithium

→

3-Bromo-5-(tert-butyldimethylsilanyloxymethyl)pyridine

5-(tert-butyldimethylsilanyloxymethyl)pyridine-3-boronic acid

收率 143.4%

溶剂

water

THF

反应条件

后处理

1. 1
   workup.ADDITIONwas added dropwise over a period of 1.5 hours
2. 2
   温度to warm to ambient temperature
3. 3
   其他The aqueous layer was separated
4. 4
   萃取extracted with diethyl ether
5. 5
   浓缩The combined organic fractions were concentrated under reduced pressure, and methanol
6. 6
   workup.ADDITIONwas added to the resulting oil
7. 7
   其他A solid formed
8. 8
   其他isolated by filtration
9. 9
   其他dried under reduced pressure

实验过程

3-Bromo-5-(tert-butyldimethylsilanyloxymethyl)pyridine was prepared according to the published procedure (Zhang, N. et al, J. Med. Chem., 45, 2832–2840 (2002)). Under a nitrogen atmosphere, a solution of 3-bromo-5-(tert-butyldimethylsilanyloxymethyl)pyridine (28.70 g, 94.94 mmol) and triisopropyl borate (26.3 mL, 114 mmol) in dry THF was cooled to −70° C. n-Butyllithium (45.6 mL, 114 mmol) was added dropwise over a period of 1.5 hours. The reaction was stirred for an additional 30 minutes and then allowed to warm to −20° C. Dilute aqueous ammonium chloride was added, and the mixture was allowed to warm to ambient temperature. The aqueous layer was separated and extracted with diethyl ether. The combined organic fractions were concentrated under reduced pressure, and methanol was added to the resulting oil. A solid formed, which was stirred with water for two days, isolated by filtration, and dried under reduced pressure to provide 18.19 g of 5-(tert-butyldimethylsilanyloxymethyl)pyridine-3-boronic acid as a white solid.

来源