C([Li])(CC)C.Br[C:7]1[CH:8]=[C:9]([CH:17]=[C:18]([Br:20])[CH:19]=1)[O:10][C:11]1[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=1.CN(C)[CH:23]=[O:24].C(O)(=O)C>CCCCCC.CCOCC>[Br:20][C:18]1[CH:19]=[C:7]([CH:8]=[C:9]([O:10][C:11]2[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=2)[CH:17]=1)[CH:23]=[O:24]
A 1.3M solution of s-butyllithium in hexane (9.2 ml) was added dropwise to a stirred solution of 3-(3,5-dibromophenoxy)pyridine (Preparation 6; 3.29 g) in dry ether (100 ml) at -78° C., and the resulting mixture was stirred at this temperature for 15 minutes. N,N-dimethylformamide (2.2 g) was then added dropwise and this mixture stirred at the same temperature for 1 hour. Glacial acetic acid (1.6 ml) was next added and the reaction solution was allowed to warm to room temperature, washed sequentially with saturated aqueous sodium bicarbonate solution and water, then dried (MgSO4). Evaporation under vacuum of the solvent gave an oil which was chromatographed on silica gel. Elution with dichloromethane first gave impurity which was followed by pure product. The product fractions were combined and evaporated under vacuum to give the title compound as an oil (1.80 g); δ (CDCl3): 7.36-7.43(4H,m), 7.76(1H,s), 8.45-8.50(2H,m), 9.90(1H,s). Found: C, 51.76; H, 2.89; N, 5.04. C12 H8BrNO2 requires C, 51.82; H, 2.90; N, 5.04%.
Wird geladen…
