Reaktion #71861

Reaktionsgleichung

ethyl 5-ethyl-1,3-oxazole-4-carboxylate

1-iodo-4-nitrobenzene

tris(2-methylphenyl)phosphine

cesium carbonate

→

title compound

Ausbeute 37.2%

Ethyl 5-ethyl-2-(4-nitrophenyl)-1,3-oxazole-4-carboxylate

Ausbeute 37.2%

Lösungsmittel

Water

Dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionfollowed by extraction with ethyl acetate
2. 2
   Waschenwashing with brine
3. 3
   TrocknenThis was dried over anhydrous magnesium sulfate
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   SonstigeThe residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=5/1, 3/1, 2/1)

Vorschrift

Dioxane (30 mL) was added to ethyl 5-ethyl-1,3-oxazole-4-carboxylate (described in Armarego, Wilfred L. F.; Taguchi, Hiroyasu; Cotton, Richard G. H.; Battiston, Sandra; Leong, Lillian; Eur. J. Med. Chem. Chim. Ther.; 22; 1987; 283-292, 1.69 g, 10 mmol), 1-iodo-4-nitrobenzene (2.74 g, 11 mmol), palladium acetate (179.6 mg, 0.8 mmol), tris(2-methylphenyl)phosphine (0.49 g, 1.6 mmol) and cesium carbonate (3.25 g, 10 mmol), and the mixture was stirred at 100° C. for 13 hours. Water was added, followed by extraction with ethyl acetate and washing with brine. This was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=5/1, 3/1, 2/1) to obtain 1.08 g of the title compound as a colorless solid (37%).

Quelle