反应详情

Tris-(dibenzylidene-acetone)-dipalladium (0.05 mmol), (2′-dicyclohexylphosphanyl-biphenyl-2-yl)-dimethyl-amine (0.1 mmol) and potassium carbonate (4.6 mmol) are suspended in 1,2-dimethoxyethane (10 ml) in an oxygen-free atmosphere (N2). 4-Bromo-benzoic acid methyl ester (3.3 mmol) and 1-isopropyl-piperazine (3.9 mmol) are added and the stirred mixture is heated under reflux for 28 hours. After cooling the solvent is evaporated and water is added to the residue, which is then extracted three times with ethyl acetate. The combined extract is dried over sodium sulfate and evaporated. The residue is purified by flash chromatography on silica gel with (CH2Cl2/MeOH=95:5) as mobile phase. The product containing fractions are combined and evaporated. The residue is suspended in diethylether/pentane and the solid filtered of and dried (vacuum). A pale-brown powder with Rf=0.23 (CH2Cl2/MeOH=95:5) is obtained.

1. temperaturethe stirred mixture is heated
2. temperatureunder reflux for 28 hours
3. temperatureAfter cooling the solvent
4. customis evaporated
5. additionwater is added to the residue, which
6. extractionis then extracted three times with ethyl acetate
7. extractionThe combined extract
8. dry with materialis dried over sodium sulfate
9. customevaporated
10. customThe residue is purified by flash chromatography on silica gel with (CH2Cl2/MeOH=95:5) as mobile phase
11. additionThe product containing fractions
12. customevaporated
13. filtrationthe solid filtered of and
14. customdried (vacuum)
15. customA pale-brown powder with Rf=0.23 (CH2Cl2/MeOH=95:5) is obtained