Reaktion #42351

Reaktionsgleichung

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

chloride

n-butyllithium

1-ethoxylmethylimidazole

→

title compound

Methyl 3-[(dipropylamino)carbonyl]-5-[1-(ethoxymethyl)-1H-imidazol-2-yl]benzoate

Lösungsmittel

ethyl acetate

diethyl ether

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is heated
2. 2
   Temperaturat reflux for 2 h
3. 3
   Waschenwashed with water, and brine
4. 4
   Trocknendried (sodium sulfate)
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigePurification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride)

Vorschrift

To a −70° C. stirred solution of 1-ethoxylmethylimidazole (J. Am. Chem. Soc. 1978, 100, 3918) (420 mg, 3.3 mmol) in tetrahydrofuran (10 mL) is added n-butyllithium (1.6 M in hexanes, 2.3 mL, 3.6 mmol). After 30 min, zinc. chloride (9.9 mL of a 1 M solution in diethyl ether, 9.9 mmol) is added and the reaction mixture is warmed to 0° C. for 1 h. To this mixture is then added methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate (1.17 g, 3 mmol) followed by palladium(0)tetrakis(triphenylphosphine) (173 mg, 0.15 mmol). The reaction mixture is heated at reflux for 2 h. The reaction mixture is diluted with ethyl acetate (50 mL)), washed with water, and brine, dried (sodium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride) provides the title compound in pure form. 1H NMR (300 MHz, CDCl3) δ 8.52 (s, 1H), 8.10 (s, 1H), 8.03 (s, 1H), 8.19 (s, 2H), 5.28 (s, 2H), 3.95 (s, 3H), 3.59 (q, J=7 Hz, 2H), 3.49 (m, 2H), 3.21 (m, 2H), 1.70 (m, 2H), 1.54 (m, 2H), 1.25 (t, J=7 Hz, 3H), 0.99 (m, 3H), 0.75 (m, 3H).

Quelle