Ammonium Chloride → Methyl 4-[(4E)-5-(5-fluoro-2-hydroxyphenyl)-3-{2-[4-(methoxycarbonyl)phenyl]ethyl}pent-4-en-1-yl]benzoate

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Reaction Steps

At 0° C., 2.95 ml (7.39 mmol) of a 2.5 M solution of n-butyllithium in hexane are slowly added dropwise to a solution of 1479 mg (3.2 mmol) of (5-fluoro-2-hydroxybenzyl)(triphenyl)phosphonium bromide in 40 ml of THF. The reaction mixture is stirred at this temperature for 45 min. At 0° C., 1080 mg (2.64 mmol) of dimethyl 4,4′-(3-formylpentane-1,5-diyl)dibenzoate in 10 ml of THF are metered in slowly. The reaction solution is stirred at 0° C. for 5 h, saturated ammonium chloride solution is then added and the mixture is diluted with water and ethyl acetate. The organic phase is separated off and the aqueous phase is extracted two more times with ethyl acetate. The combined organic phases are dried over sodium sulfate and filtered, and the solvent is removed to dryness. The crude product obtained is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 4:1). This gives 529 mg (1.11 mmol, 42% of theory) of a colorless oil.

Provenance & Evidence