Cesium carbonate → 4-Bromo-1-chloro-2-(4-(2-cyclopropoxyethoxy)benzyl)benzene

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Reaction Steps

A mixture of 4-(5-bromo-2-chlorobenzyl)phenol (56.7 g, 210 mmol) and Cs2CO3 (135 g, 420 mmol) in DMF (350 mL) was stirred at room temperature for 30 min, and then 2-cyclopropoxyethyl 4-methylbenzenesulfonate (crude intermediate BP from the second preceeding step above) (53.3 g, 210 mmol) was added. The reaction mixture was stirred at room temperature overnight, and then diluted with water (3 L) and extracted with EtOAc. The organic layer was washed with water, then with brine, and dried over Na2SO4. The residue was concentrated and then purified by flash column chromatography on silica gel (eluent PE:EA=10:1) to give intermediate DK as a liquid (51 g, yield 64%). 1H NMR (CDCl3, 400 MHz): δ 7.22˜7.29 (m, 3H), 7.08 (d, J=8.8 Hz, 2H), 6.88 (d, J=8.8 Hz, 2H), 4.10 (t, J=4.8 Hz, 2H), 3.86 (t, J=4.8 Hz, 2H), 3.38-3.32 (m, 1H), 0.62-0.66 (m, 2H), 0.49-0.52(m, 2H).

Provenance & Evidence