تفاعل #42340

معادلة التفاعل

n-butyllithium

1-tert-butyldimethylsilylimidazole

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

→

title compound

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

المذيبات

ethyl acetate

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe reaction mixture is heated
2. 2
   درجة الحرارةat reflux for 15 h
3. 3
   غسيلwashed with water, and brine
4. 4
   تجفيفdried (sodium sulfate)
5. 5
   ترشيحfiltered
6. 6
   تركيزconcentrated under reduced pressure
7. 7
   أخرىPurification by flash column chromatography (silica gel, 1-5% methanol/methylene chloride)

الإجراء التجريبي

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).

المصدر