Reacción #8830

Ecuación de reacción

tributyltin chloride

tert-butyllithium

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

ammonium chloride

→

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

Rendimiento 49.0%

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Temperaturato warm to −20° C.
3. 3
   TemperaturaThe reaction was cooled again to −78° C.
4. 4
   workup.WAITto reach room temperature overnight
5. 5
   Extracciónthe product extracted with dichloromethane
6. 6
   SecadoThe combined organics were dried over magnesium sulfate
7. 7
   Otrothe solvent was evaporated
8. 8
   Otroresidue purified by flash chromatography
9. 9
   Lavadoeluting with 20% ethyl acetate in hexanes

Procedimiento

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.

Fuente