2-Aminopyrimidine-5-boronic Acid Pinacol Ester

7752-82-1

73183-34-3

402960-38-7

General procedure for the synthesis of 2-aminopyrimidine-5-boronic acid pinacol ester from 2-amino-5-bromopyrimidine and bis(pinacolato)diboron and 5.9 g (60.3 mmol) potassium acetate: 3.5 g (20.1 mmol) 5-bromopyrimidin-2-amine, 5.6 g (22.1 mmol) bis(pinacolato)diboron, and 5.9 g (60.3 mmol) potassium acetate were dissolved in 35 mL of 1,4-dioxane and subsequently 1.41 g (2.01 mmol) of bis(triphenylphosphine)dichloropalladium(II) was added. The reaction mixture was stirred at 110 °C for 4 hours. After completion of the reaction, it was cooled to room temperature, diluted with ethyl acetate and sonicated for 5 minutes. It was filtered through a diatomaceous earth filled filter and washed with ethyl acetate. The filtrate was washed sequentially with distilled water and saturated saline. The organic layer was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was dissolved in 100 mL of a solvent mixture of dichloromethane and hexane (1:3, v/v) and stirred at room temperature for 1 hour. It was filtered under reduced pressure and the resulting solid was dried under reduced pressure to give 4 g (yield: 90%) of the target product 2-aminopyrimidine-5-boronic acid pinacol ester.