Dichloromethane → 2'-Cyclohexyl-5'-isopropoxy-4'-methoxyacetophenone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A magnetically stirred solution of bromocyclohexane (0.18 mL, 1.46 mmol) in dry Et2O (3.0 mL), under a nitrogen atmosphere, was cooled to −78° C. and treated, dropwise, with tert-butyllithium (1.7 M in pentane, 1.9 mL, 3.23 mmol). After 10 minutes, the mixture was treated, dropwise, with a solution of anhydrous zinc iodide (495 mg, 1.55 mmol) in dry THF (1.7 mL). After 10 minutes at −78° C., the reaction mixture was allowed to warm to 18° C. and then slowly transferred to a mixture of iodide 9 (370 mg, 1.11 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II).CH2Cl2 (18 mg, 0.022 mmol) and copper(I) iodode (8 mg, 0,042 mmol) in N,N-dimethylacetamide (1.0 mL). The resulting mixture was then stirred at 60° C., under a nitrogen atmosphere, for 6 h. The cooled mixture was filtered through a pad of Celite™ and the solids thus retained washed with EtOAC (1×50 mL). The filtrate was then washed with HCl (1×10 mL of a 1.0 M aqueous solution) and brine (1×10 mL), then dried (MgSO4), filtered and concentrated under reduced pressure and the ensuing residue subjected to flash chromatography (1:19→1:9 v/v ethyl acetate/hexane gradient elution) to afford the title compound 52 (65 mg, 20%) as a yellow oil, Rf 0.7 in 1:1 v/v ethyl acetate/hexane.

Herkunft & Nachweise