Cyclopropylboronic acid → (5-Cyclopropyl-2,4-dimethyl-phenyl)-acetic acid methyl ester

Participants

Reaction Steps

To a solution of 6.0 g of (5-bromo-2,4-dimethyl-phenyl)-acetic acid methyl ester (WO99/48869) in 100 ml of toluene is added 2.2 g of cyclopropylboronic acid and 20 g of potassium phosphate tribasic trihydrate at room temperature. The reaction mixture is stirred for 5 minutes under nitrogen atmosphere, followed by further addition of 1.2 g of tetrakis(triphenylphosphine)palladium(0). After heating and stirring for 16 hours at 110° C., the reaction mixture is filtered, the solvent removed in vacuo and the residue is subjected to silica gel chromatography (isohexane/diethyl ether 2:1) to yield 2.5 g of (5-cyclopropyl-2,4-dimethyl-phenyl)-acetic acid methyl ester.

Provenance & Evidence