Ammonium Chloride → Ethyl 6-(3,5-difluoro-4-triisopropylsilanyloxybenzyl)-8-[5-fluoro-2-(4'-trifluoromethylbiphenyl-4-ylmethoxy)phenyl]oct-7-enoate

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Reaction Steps

0.7 ml (1.12 mmol) of a 1.6 M solution of n-butyllithium in hexane is added dropwise to a suspension of 784 mg (1.06 mmol) of [5-fluoro-2-(4′-trifluoromethylbiphenyl-4-ylmethoxy)-benzyl]triphenylphosphonium bromide in 10 ml of THF at 0° C. and then stirred for 45 min. Subsequently, a solution of 500 mg (1.06 mmol) of ethyl 7-(3,5-difluoro-4-triisopropylsilanyloxy-phenyl)-6-formylheptanoate in 10 ml of THF is added dropwise at 0° C. and then stirred at this temperature for 2 h. The mixture is mixed with saturated ammonium chloride solution and extracted with ethyl acetate. The combined organic phases are dried over sodium sulfate and concentrated. The resulting crude product is purified by chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 7:1). 813 mg (84% of theory) of the title compound are obtained as an E/Z mixture (2:1).

Provenance & Evidence