Dichloromethane → 6-Methanesulfonyloxy-2-(4-methanesulfonyloxyphenyl)-3-[4-(2-bromoethoxy)benzoyl]benzo[b]thiophene

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Reaction Steps

One g. of 4-(2-bromoethoxy)benzoic acid was converted to the acid chloride, and was combined with 1.2 g. of 6-methanesulfonyloxy-2-(4-methanesulfonyloxyphenyl)benzo[b]thiophene, 20 ml. of dichloromethane and 0.5 ml. of trifluoromethanesulfonic acid. The mixture was stirred under reflux overnight, and was then poured into ice-water. The organic layer was separated, washed with sodium carbonate solution, dried and evaporated under vacuum to obtain 2.1 g. of brown oil. The oil was chromatographed over a 4×8 cm. silica gel column with 9/1 toluene/ethyl acetate and the product-containing fractions were combined and evaporated under vacuum to obtain 1.8 g. of purified product as an oil. The product was identified by its MH+ molecular ion, m/e 626, in the field desorption mass spectrum and by an absorption maximum in the infrared spectrum, in chloroform, at 1645 cm.-1 attributable to the CO function. A small sample was recrystallized from methanol to obtain white crystals, m.p. 105°-107°.

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