Hydrochloric Acid → HCID 22227474, compound

Participants

Reaction Steps

A solution of 4.8 g of 1,1,2,2,8-pentafluoro-1,2-dihydronaphthalene [(Z3) where R1=H] in 75 ml of tetrahydrofuran was mixed with 11 ml of sec-butyllithium (2M in pentane) at a temperature below −75° C. After 3 g of trimethyl borate had been added, the mixture was stirred at the same temperature for 3 hours and subsequently brought to room temperature overnight. After hydrolysis using 10% hydrochloric acid, 150 ml of tert-butyl methyl ether were added, and the organic phase was separated off, washed with water and sodium chloride solution and dried. The 1,1,2,2,8-pentafluoro-1,2-dihydronaphthalene-7-boronic acid obtained was reacted with the equimolar amount of 4-propylbromobenzene, 2 mol-equivalents of sodium carbonate and 1 mol % of tetrakis(triphenylphosphine)palladium(0) in 50 ml of an ethanol/toluene/water 1:2:1 (vol.) mixture by refluxing for one day. After conventional work-up, the organic fraction was subjected to chromatographic purification (silica gel, toluene/heptane 2:1), the product-containing fractions were combined, the solvent mixture was distilled off under reduced pressure, and the residue was recrystallised from acetonitrile, giving 1.6 g of 1,1,2,2,8-pentafluoro-7-(4-propylphenyl)-1,2-dihydronaphthalene.

Provenance & Evidence