Br[C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([C:10]([O:12][CH3:13])=[O:11])=[C:7]([CH3:14])[C:6]=2[CH:15]=1.[CH3:16][O:17][CH2:18][CH2:19][NH:20][CH3:21].C(=O)([O-])[O-].[Cs+].[Cs+].CC1(C)C2C=CC=C(P(C3C=CC=CC=3)C3C=CC=CC=3)C=2OC2C1=CC=CC=2P(C1C=CC=CC=1)C1C=CC=CC=1>C1(C)C=CC=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[CH3:16][O:17][CH2:18][CH2:19][N:20]([CH3:21])[C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([C:10]([O:12][CH3:13])=[O:11])=[C:7]([CH3:14])[C:6]=2[CH:15]=1To a solution (50 mL) of methyl 5-bromo-3-methyl-1-benzofuran-2-carboxylate (2.7 g) synthesized in Example A186(1) in toluene were added 2-methoxy-N-methylethanamine (2.7 g), cesium carbonate (9.8 g), tris(dibenzylideneacetone)dipalladium (0) (0.69 g) and 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (0.87 g), and the mixture was heated under reflux under argon atmosphere for 6 hr. The reaction mixture was cooled to room temperature, and filtered through celite, water was added to the filtrate, and the mixture was extracted with ethyl acetate. The extract was concentrated, and the residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:4, volume ratio) to give the title object compound (2.7 g, quantitative) as a yellow oil.
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