Hydrochloric Acid → HCID 54508553, compound

Participants

Reaction Steps

A solution of 2.5 g of 2-fluoro-3-octyloxybenzaldehyde (prepared by reacting 2-octyloxyfluorobenzene with lithium diisopropylamide followed by reaction with N,N-dimethylformamide) in 50 ml of THF is added dropwise at 20° C. to a fully reacted mixture of 5.6 g of 2-fluoro-3-octyloxybenzyltriphenylphosphoniumbromide (prepared by the reaction sequence: reaction of 2-fluoro-3-octyloxybenzaldehyde with LiAlH4 in THF to give fluoro-3-octyloxybenzyl alcohol, reaction of the latter with triphenylphosphine/Br2 to give 2-fluoro-3-octyloxybenzyl bromide and reaction of the latter with triphenylphosphine in toluene) and 1.2 g of potassium tert-butoxide in 100 ml of THF. When the reaction is complete, the mixture is adjusted to pH 5 using HCl, 500 ml of H2O are added, and the mixture is extracted three times with 100 ml of diethyl ether in each case. Chromatography on silica gel using dichloromethane/heptane 1:1 gives 1,2-bis(2-fluoro-3-octyloxyphenyl)ethene as an E/Z-mixture. The latter is dissolved in cyclohexane, 4 mol % of iodine are added, and the mixture is exposed to UV light for 8 hours at 25° C. in a quartz apparatus. Chromatography on SiO2 using dichloromethane and recrystallization from acetonitrile give 1.2 g of 1,8-difluoro-2,7-dioctyloxyphenanthrene as colorless crystals.

Provenance & Evidence