反应详情

4-Carboxybenzeneboronic acid methyl ester (248 mmol) from A, 4-bromopyridine (248 mmol), tetrakis-(triphenylphosphin)-palladium (2.5 mmol) and potassium carbonate (744 mmol) are suspended in 1,2-dimethoxyethane (1100 ml). The stirred mixture is heated under reflux for 8 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 suspended in diethylether and the solid filtered of and dried (vacuum). A pale-brown powder with mp. 99-101° C., Rf=0.39 (CH2Cl2/MeOH=95:5) is obtained.

1. temperatureThe stirred mixture is heated
2. temperatureunder reflux for 8 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. filtrationthe solid filtered of and
11. customdried (vacuum)
12. customA pale-brown powder with mp. 99-101° C., Rf=0.39 (CH2Cl2/MeOH=95:5) is obtained