반응 #42340

반응 방정식

n-butyllithium

1-tert-butyldimethylsilylimidazole

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

→

title compound

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

용매

ethyl acetate

tetrahydrofuran

반응 조건

후처리

1. 1
   온도The reaction mixture is heated
2. 2
   온도at reflux for 15 h
3. 3
   세척washed with water, and brine
4. 4
   건조dried (sodium sulfate)
5. 5
   여과filtered
6. 6
   농축concentrated under reduced pressure
7. 7
   기타Purification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride)

실험 절차

To a −70° C. stirred solution of 1-tert-butyldimethylsilylimidazole (602 mg, 3.3 mmol) in tetrahydrofuran (10 mL) is added n-butyllithium (1.6 M in hexanes, 2.3 mL, 3.63 mmol). After 30 min, zinc chloride (1 M in diethyl ether, 9.9 mL, 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 prepared by the method in Example SP-281, step 2 (1.17 g, 3 mmol) followed by palladium(0)tetrakis(triphenylphosphine) (173 mg, 0.15 mmol). The reaction mixture is heated at reflux for 15 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 8.64 (s, 1H), 8.14 (s, 1H), 7.97 (s, 1H), 7.19 (s, 2H), 3.96 (s, 3H), 3.51 (m, 2H), 3.32 (m, 2H), 1.73 (m, 2H), 1.57 (m, 2H), 1.01 (m, 3H), 0.73 (m, 3H).

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