COB([C:5]1[CH:10]=[CH:9][C:8]([C:11]([OH:13])=[O:12])=[CH:7][CH:6]=1)O.Br[C:15]1[CH:20]=[CH:19][N:18]=[CH:17][CH:16]=1.[C:21](=O)([O-])[O-].[K+].[K+]>COCCOC.[Pd].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:21][O:13][C:11](=[O:12])[C:8]1[CH:7]=[CH:6][C:5]([C:15]2[CH:20]=[CH:19][N:18]=[CH:17][CH:16]=2)=[CH:10][CH:9]=14-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.
読み込み中…
