تفاعل #8830

معادلة التفاعل

tributyltin chloride

tert-butyllithium

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

ammonium chloride

→

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

المردود 49.0%

المذيبات

THF

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONAfter the addition
2. 2
   درجة الحرارةto warm to −20° C.
3. 3
   درجة الحرارةThe reaction was cooled again to −78° C.
4. 4
   workup.WAITto reach room temperature overnight
5. 5
   استخلاصthe product extracted with dichloromethane
6. 6
   تجفيفThe combined organics were dried over magnesium sulfate
7. 7
   أخرىthe solvent was evaporated
8. 8
   أخرىresidue purified by flash chromatography
9. 9
   غسيلeluting with 20% ethyl acetate in hexanes

الإجراء التجريبي

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.

المصدر