Hexachloroethane → 7-Chloro-1,6-dimethoxynaphthalene

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A 0.5 L round bottom flask equipped with magnetic stirring bar and thermometer was charged with 1,6-dimethoxynaphtalene (14.56 g, 77.36 mmol), THF (50 ml) and resultant solution was cooled to −78° C. (acetone/dry ice bath). Solution of butyl lithium (1.6 M in hexane, 53.18 ml, 85.09 mmol) was added through a syringe during 10 min. Mixture was allowed to warm to room temperature and stirred for 20 h. Then reaction mixture was cooled again to −78° C. and solution of hexachloroethane (20.144 g, 85.09 mmol) in THF (50 ml) was added through a syringe during 10 min. Reaction mixture was allowed to warm to room temperature, diluted with 1N HCl (150 ml), EtOAc (200 ml) and transferred into separation funnel. Organic phase was washed with saturated NaCl solution (2×30 ml), dried over MgSO4 and concentrated in vacuum. Residue was purified by vacuum flash chromatography (SiO2, 150 g, 35-65 m, eluent 10% EtOAc in hexane) to give a mixture (˜3:2) of 47 and 46. Pure desired product (47) was obtained by multiple crystallizations from ether (5.0 g, 22.5 mmol, yield=29%) as white solid. 1H NMR (CDCl3): δ 8.38 (s, 1H), 7.49-7.37 (m, 3H), 6.82 (dd, J=7.2, 1.0 Hz; 1H), 4.11 (s, 3H), 4.08 (s, 3H).

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