Methylboronic Acid → 4-(3,5,6-Trimethylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a mixture of 4-(3,5,6-trichloropyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9.27 g) described in Preparation Example 173, palladium (II) acetate (851 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (3.11 g), potassium fluoride (17.6 g) and methylboronic acid (9.08 g) was added tetrahydrofuran (190 mL), and the mixture was refluxed for 5.5 hr. After cooling, to the reaction mixture were added ethyl acetate and saturated brine and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and dried over sodium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by column chromatography (hexane:ethyl acetate) to give the title compound (7.08 g).

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