Ammonium Chloride → Methyl E-4-[3-(3,5-difluoro-4-triisopropylsilanyloxybenzyl)-5-(2-hydroxyphenyl)pent-4-enyl]-benzoate

Participants

Reaction Conditions

Reaction Steps

7.49 ml (11.98 mmol) of a 1.6 M solution of n-butyllithium in hexane are slowly added to a solution of 2.38 g (5.14 mmol) of (2-hydroxybenzyl)triphenylphosphonium bromide in 50 ml of THF at 0° C. Then, at this temperature, 2.16 g (4.28 mmol) of methyl 4-[3-(3,5-difluoro-4-triisopropylsilanyloxybenzyl)-4-oxobutyl]benzoate are slowly metered in. The reaction solution is stirred at 0° C. for 2 hours and then mixed with 100 ml of saturated ammonium chloride solution and extracted with diethyl ether. The combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulfate. After filtration, the solvent is concentrated to dryness. The resulting crude product is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 10:1). 2.37 g (90% of theory) of a colorless solid are obtained.

Provenance & Evidence