[Br:1][C:2]1[CH:7]=[CH:6][C:5](I)=[CH:4][CH:3]=1.[Li]CCCC.[O:14]=[C:15]1[CH2:18][N:17]([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[CH2:16]1>O1CCCC1.C(OCC)C.C1COCC1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:15]2([OH:14])[CH2:16][N:17]([C:19]([O:21][C:22]([CH3:24])([CH3:23])[CH3:25])=[O:20])[CH2:18]2)=[CH:4][CH:3]=1Into a 1-L 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed a solution of 1-bromo-4-iodobenzene (25.0 g, 88.4 mmol) in tetrahydrofuran/diethyl ether (400/200 mL). The solution was cooled to −78° C. then n-BuLi (2.5 M, 37.1 mL, 92.8 mmol) was added drop-wise over 10 min. To the resulting mixture was added tert-butyl 3-oxoazetidine-1-carboxylate (16.6 g, 97.0 mmol) in THF (100 mL) drop-wise at −78° C. The resulting mixture was stirred for 1.5 h at −78° C., then carefully quenched with water (300 mL). The aqueous phase was extracted with ethyl acetate (200 mL) and the combined organic layers were washed with brine (2×100 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1:20-1:5) as the eluent followed by re-crystallized from ethyl acetate:PE in the ratio of 1:100 to yield 8.0 g (28%) of the title compound as a white solid.
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