Reaktion #80189

Reaktionsgleichung

2-(Isopropylcarboxy)-phenylboronic acid

2-chloro-5-trifluoromethylpyridine

→

title compound

Ausbeute 70.0%

2-(5-Trifluoromethyl-pyridin-2-yl)-benzoic acid isopropyl ester

Ausbeute 70.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe reaction vessel purged
2. 2
   workup.ADDITION8 ml of a 10% sodium carbonate solution was added
3. 3
   Temperaturthe reaction mixture was heated
4. 4
   Temperaturat reflux for 1.5 h
5. 5
   ExtraktionThe resulting mixture was extracted with ethyl acetate
6. 6
   Trocknenthe combined organic layers dried (magnesium sulfate)
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under vacuum
9. 9
   SonstigePurification of the residue by column chromatography
10. 10
    Wascheneluting with 10% ethyl acetate in hexanes

Vorschrift

2-(Isopropylcarboxy)-phenylboronic acid (S. Caron and J. M. Hawkins, J. Org. Chem. 1998, 63, 2054-2055) (2.2 g, 10.6 mmol) and 2-chloro-5-trifluoromethylpyridine (500 mg, 2.75 mmol) were dissolved in toluene. Tetrakis(triphenylphosphine)palladium (160 mg, 0.14 mmol) was added and the reaction vessel purged by alternating vacuum and nitrogen gas three times. 8 ml of a 10% sodium carbonate solution was added and the reaction mixture was heated at reflux for 1.5 h. The resulting mixture was extracted with ethyl acetate, the combined organic layers dried (magnesium sulfate), filtered and concentrated under vacuum. Purification of the residue by column chromatography eluting with 10% ethyl acetate in hexanes provided the title compound in approximately 70% yield.

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