Sodium Carbonate → 1-(4-Ethylpiperazin-1-yl)-3-[4-(2-benzyloxyethyl)phenyl]isoquinoline

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Reaction Steps

4-(2-Benzyloxyethyl)phenylboric acid (0.40 g) and 3-bromo-1-(4-ethylpiperazin-1-yl)isoquinoline (0.65 g) were heated under reflux in the presence of tetrakistriphenylphosphinepalladium(0) (0.09 g) in toluene (50 ml) and a 10% aqueous solution of sodium carbonate (30 ml) in nitrogen atmosphere for 1 hr. To the mixture was additionally added 4-(2-benzyloxyethyl)phenylboric acid (0.40 g), and the mixture was heated under reflux for 1.5 hr. 4-(2-Benzyloxyethyl)phenylboric acid (0.40 g) was again added, and the mixture was heated under reflux overnight. The organic layer was separated, and it was extracted with 2N hydrochloric acid twice. The resulting aqueous layer was washed with ethyl acetate, adjusted to pH 10 with a 8N aqueous solution of sodium hydroxide, extracted with ethyl acetate, washed with a 10% aqueous solution of sodium carbonate and brine, and then dried over magnesium sulfate. The solvent was evaporated, and the resulting residue was purified by silica gel column chromatography (chloroform/methanol system, and then ethyl acetate/acetone system), to give 1-(4-ethylpiperazin-1-yl)-3-[4-(2-benzyloxyethyl)phenyl]isoquinoline (0.48 g) as a colorless viscous oil.

Provenance & Evidence