반응 #9472

반응 방정식

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

수율 143.4%

용매

water

THF

반응 조건

후처리

1. 1
   workup.ADDITIONwas added dropwise over a period of 1.5 hours
2. 2
   온도to warm to ambient temperature
3. 3
   기타The aqueous layer was separated
4. 4
   추출extracted with diethyl ether
5. 5
   농축The combined organic fractions were concentrated under reduced pressure, and methanol
6. 6
   workup.ADDITIONwas added to the resulting oil
7. 7
   기타A solid formed
8. 8
   기타isolated by filtration
9. 9
   기타dried under reduced pressure

실험 절차

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.

출처