Reaktion #8313

Reaktionsgleichung

triethylamine

ethyl 4-bromoquinoline-2-carboxylate

triethylamine

2-ethynylpyridine

→

yellow solid

Ausbeute 50.3%

4-Pyridin-2-ylethynyl-quinoline-2-carboxylic acid ethyl ester

Ausbeute 50.3%

Lösungsmittel

CH3CN

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture heated for an additional 18 h
2. 2
   EinengenThe mixture is concentrated in vacuo
3. 3
   Sonstigepartitioned between water and chloroform
4. 4
   WaschenThe chloroform extracts are washed with brine
5. 5
   Sonstigeevaporated
6. 6
   SonstigeThe residue is chromatographed on SiO2 (50% ethyl acetate/hexanes)

Vorschrift

A mixture of ethyl 4-bromoquinoline-2-carboxylate (2.80 g, 10.0 mmol, J. Org. Chem. 1947, 12, 456), triethylamine (1.7 mL, 12 mmol), bis(triphenylphosphine)-palladium(II)chloride (0.561 g, 0.80 mmol), CuI (0.114 g, 0.60 mmol), and 2-ethynylpyridine (1.11 g, 10.8 mmol) in CH3CN (80 mL) is heated at 75-80° C. for 18 h in a sealed tube. Additional triethylamine (0.85 ml, 6.1 mmol), bis(triphenylphosphine)palladium (II) chloride (0.23 g, 0.40 mmol), and CuI (0.055 g, 0.29 mmol) is added and the mixture heated for an additional 18 h. The mixture is concentrated in vacuo and partitioned between water and chloroform. The chloroform extracts are washed with brine and evaporated. The residue is chromatographed on SiO2 (50% ethyl acetate/hexanes) to yield 1.52 g (50%) of a yellow solid. Precipitation from ethyl acetate gave the title compound as yellow crystals: mp 129-131° C.; MS ES+ m/e 303 (M+1).

Quelle