Reaktion #8319

Reaktionsgleichung

citric acid

6-trifluoromethyl-pyridine-2-carbothioic acid S-(4-chloro-phenyl) ester

4-fluorophenylacetonitrile

potassium bis(trimethylsilyl)amide

→

2-(4-fluoro-phenyl)-3-oxo-3-(6-trifluoromethyl-pyridin-2-yl)-propionitrile

Ausbeute 66.0%

Lösungsmittel

methylene chloride

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto warn to room temperature
2. 2
   Temperaturthen warmed
3. 3
   Temperaturto reflux for 10 min, at which time the reaction
4. 4
   Temperaturto cool
5. 5
   Extraktionextracted into methylene chloride
6. 6
   TrocknenThe methylene chloride solution is dried over magnesium sulfate
7. 7
   Einengenconcentrated in vacuo
8. 8
   SonstigeThe residue is purified on a silica gel cartridge
9. 9
   Sonstigeprepared with hexane
10. 10
    Waschenthen eluted with methylene chloride

Vorschrift

A solution of 4-fluorophenylacetonitrile (0.12 mL, 1.0 mmol) in dry tetrahydrofuran (2 mL) is treated dropwise with potassium bis(trimethylsilyl)amide (0.5 M toluene, 3.0 mL, 1.5 mmol) at 0° C. under an atmosphere of nitrogen. The mixture is stirred 10 min then 6-trifluoromethyl-pyridine-2-carbothioic acid S-(4-chloro-phenyl) ester is added all at once. The mixture is allowed to warn to room temperature then warmed to reflux for 10 min, at which time the reaction is complete by TLC (methylene chloride). The mixture is allowed to cool then poured into 10% citric acid and extracted into methylene chloride. The methylene chloride solution is dried over magnesium sulfate and concentrated in vacuo. The residue is purified on a silica gel cartridge prepared with hexane then eluted with methylene chloride to yield 204 mg (66%) 2-(4-fluoro-phenyl)-3-oxo-3-(6-trifluoromethyl-pyridin-2-yl)-propionitrile. MS ES− m/z 307 (M−1).

Quelle