반응 #42350
ord-13f72cbfbaea442d8cdb7ad596d52041
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반응물
반응 조건
후처리
- 1기타without further purification
- 2기타in the following reaction
- 3온도The reaction mixture is heated
- 4온도at reflux for 3 h
- 5온도The reaction mixture is cooled
- 6여과filtered
- 7세척washed with saturated sodium bicarbonate, water, and brine
- 8건조dried (sodium sulfate)
- 9여과filtered
- 10농축concentrated under reduced pressure
- 11기타Purification by flash column chromatography (silica gel, 60% ethyl acetate/hexane)
실험 절차
3-[(Dipropylamino)carbonyl]-5-iodobenzoic acid (12 g, 32 mmol) is dissolved in 20% methanol/benzene (480 mL), and 2M trimethylsilyldiazomethane in hexane (19 mL, 38 mmol) is added slowly. Upon completion of the addition, the solution is concentrated under reduced pressure to give methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate for use without further purification in the following reaction. To a −70° C. stirred solution of oxazole (120 mg, 1.7 mmol) in tetrahydrofuran (4 mL) is added n-butyllithium (1.6 M in hexanes, 1.2 mL, 1.9 mmol). After 30 min, zinc chloride (1 M in diethyl ether, 5.2 mL, 5.2 mmol) is added and the reaction mixture is warmed to 0° C. for 1 h. To this mixture is added a solution of methyl 3-[(dipropylamino)carbonyl]-5-iodobenzoate (643 mg, 1.6 mmol) in anhydrous tetrahydrofuran (3 mL) followed by palladium(0)tetrakis(triphenylphosphine) (80 mg, 0.07 mmol). The reaction mixture is heated at reflux for 3 h. The reaction mixture is cooled, diluted with ethyl acetate, filtered, washed with saturated sodium bicarbonate, water, and brine, dried (sodium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, 60% ethyl acetate/hexane) provides the title compound in pure form. 1H NMR (400 MHz, CDCl3) δ 8.77 (s, 1H), 8.27 (s, 1H), 8.14 (s, 1H), 7.80 (s, 1H) 7.32 (s, 1H), 3.52 (t, 2H), 3.22 (t, 2H), 1.75 (m, 2H), 1.30 (m, 2H), 0.97 (t, 3H), 0.79 (t, 3H).