Cl[CH2:2][C:3]1[N:4]=[C:5]([CH:8]=[CH:9][C:10]2[CH:15]=[CH:14][C:13]([C:16]([F:19])([F:18])[F:17])=[CH:12][CH:11]=2)[O:6][CH:7]=1.[Br:20][C:21]1[N:22]=[CH:23][C:24]([OH:27])=[N:25][CH:26]=1.C(=O)([O-])[O-].[Cs+].[Cs+].C(OCC)(=O)C>CN(C=O)C>[Br:20][C:21]1[CH:26]=[N:25][C:24]([O:27][CH2:2][C:3]2[N:4]=[C:5]([CH:8]=[CH:9][C:10]3[CH:15]=[CH:14][C:13]([C:16]([F:19])([F:18])[F:17])=[CH:12][CH:11]=3)[O:6][CH:7]=2)=[CH:23][N:22]=1A mixture of 4-chlormethyl-2-[2-(4-trifluoromethyl-phenyl)-vinyl]-oxazole (0.345 g, 1.2 mmol), 5-bromo-pyrazin-2-ol (0.175 g, 1.0 mmol) and cesium carbonate (Cs2CO3) (0.489 g, 1.5 mmol) in DMF (4 ml) is kept at 80° C. for 1 h. After cooling ethyl acetate (40 ml) is added, the mixture is washed with sat. NH4Cl and brine, dried over MgSO4 and concentrated in vacuo. The crude product is purified by flash column chromatography (ethyl acetate/hexane 1:9->ethyl acetate/hexane 1:2) yielding 2-bromo-5-{2-[2-(4-trifluoromethyl-phenyl)-vinyl]-oxazol-4-yl-methoxy}-pyrazine as a white solid. Yield 122 mg (29%).
Wird geladen…