反応 #8830

反応方程式

tributyltin chloride

tert-butyllithium

Pyridin-4-yl-carbamic acid tert-butyl ester

ammonium chloride

→

(3-tributylstannyl-pyridin-4-yl)-carbamic acid tert-butyl ester

収率 49.0%

溶媒

THF

反応条件

後処理

1. 1
   workup.ADDITIONAfter the addition
2. 2
   温度to warm to −20° C.
3. 3
   温度The reaction was cooled again to −78° C.
4. 4
   workup.WAITto reach room temperature overnight
5. 5
   抽出the product extracted with dichloromethane
6. 6
   乾燥The combined organics were dried over magnesium sulfate
7. 7
   その他the solvent was evaporated
8. 8
   その他residue purified by flash chromatography
9. 9
   洗浄eluting with 20% ethyl acetate in hexanes

実験手順

Pyridin-4-yl-carbamic acid tert-butyl ester (1.74 g, 8.95 mmol) (prepared as described in Venuti et al, J. Med. Chem. 1988, 31(11), 2136–45) dissolved in THF (150 mL) was cooled to −78° C. and a solution of 1.7M tert-butyllithium in hexanes (11.6 mL, 19.70 mmol) was added dropwise. After the addition, the stirring was continued for 1 h to −78° C. and the solution was then allowed to warm to −20° C. and stirred for an additional 3 h. The reaction was cooled again to −78° C. and tributyltin chloride (2.91 mL, 10.74 mmol) was added dropwise and the reaction was allowed to reach room temperature overnight. A saturated ammonium chloride solution was added and the product extracted with dichloromethane. The combined organics were dried over magnesium sulfate, the solvent was evaporated and residue purified by flash chromatography eluting with 20% ethyl acetate in hexanes to yield 2.12 g of (3-tributylstannyl-pyridin-4-yl)-carbamic acid tert-butyl ester.

出典