Reaktion #42571

Reaktionsgleichung

2-triethylstannyloxazole

methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate

→

methyl 3-[(dipropylamino)carbonyl]-5-(1,3-oxazol-2-yl)benzoate

Ausbeute 27.8%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigepurged with argon
2. 2
   Sonstigethe reaction mixture was degassed under reduced pressure for 15 min
3. 3
   Sonstigepurged with argon
4. 4
   TemperaturThe reaction mixture was heated
5. 5
   Temperaturat reflux for 2 d
6. 6
   workup.ADDITIONdiluted with ethyl acetate
7. 7
   Waschenwashed with water (3×50 mL)
8. 8
   Trocknendried (sodium sulfate)
9. 9
   Einengenconcentrated under reduced pressure
10. 10
    SonstigePurification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes)

Vorschrift

A stirred solution of 2-triethylstannyloxazole (Chem. Mater. 1994, 6, 1023) (1.5 g, 5.5 mmol) and methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate (1.8 g, 4.6 mmol) in dimethylformamide (12 mL) was degassed under reduced pressure for 15 min and purged with argon. Palladium(0)tetrakis(triphenylphosphine) (158 mg, 0.14 mmol) was added and the reaction mixture was degassed under reduced pressure for 15 min and then purged with argon. The reaction mixture was heated at reflux for 2 d, cooled to room temperature, diluted with ethyl acetate, washed with water (3×50 mL), dried (sodium sulfate), and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes) provided methyl 3-[(dipropylamino)carbonyl]-5-(1,3-oxazol-2-yl)benzoate (423 mg): 1H NMR (300 MHz, CDCl3) δ 8.73 (s, 1H), 8.23 (s, 1H), 8.11 (s, 1H), 7.76 (s, 1H), 7.28 (s, 1H), 3.97 (s, 3H), 3.49 (br s, 2H), 3.18 (br s, 2H), 1.72 (d, J=7 Hz, 2H), 1.55 (d, J=7 Hz, 2H), 1.00 (t, J=7 Hz, 3H), 0.75 (t, J=7 Hz, 3H).

Quelle