Reaktion #8985

Reaktionsgleichung

Triphenylphosphine

2-Chloro-4-iodo-pyridine

trimethylsilylacetylene

→

desired product

2-Chloro-4-trimethylsilanylethynyl-pyridine

Lösungsmittel

triethyl amine

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThis mixture was evacuated
2. 2
   Sonstigeto remove oxygen from the solution
3. 3
   workup.STIRRINGThe reaction mixture was stirred at room temperature overnight
4. 4
   SonstigeThe solvent was evaporated
5. 5
   Extraktionextracted three times with ethyl acetate (500 mL each)
6. 6
   TrocknenThe combined organic extracts were dried with magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Sonstigeevaporated
9. 9
   SonstigeThe crude product was purified by chromatography on silica gel (cyclohexane/ethyl acetate 80:20)

Vorschrift

2-Chloro-4-iodo-pyridine (10.0 g, 41.8 mmol) was dissolved in 200 mL of dry THF and 17.5 mL of triethyl amine. This mixture was evacuated and backfilled with argon several times to remove oxygen from the solution. Triphenylphosphine (329 mg, 1.25 mmol) and bis(triphenylphosphine)palladium(II)chloride (1.47 g, 2.09 mmol) were added and the reaction mixture was stirred at room temperature for 1 h. Copper(I)iodide (239 mg, 1.25 mmol) and trimethylsilylacetylene (6.28 g, 6.39 mmol) were added. The reaction mixture was stirred at room temperature overnight. The solvent was evaporated. The residue was taken up in 500 mL of water and extracted three times with ethyl acetate (500 mL each). The combined organic extracts were dried with magnesium sulfate, filtered and evaporated. The crude product was purified by chromatography on silica gel (cyclohexane/ethyl acetate 80:20). The desired product was obtained as a light brown semi solid (10 g,>100%). This material was used without any further purification for the next step.

Quelle