Methane → 2-(4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethan-1-ol

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Reaction Steps

A solution of 1,3-dioxolan-2-one (2.496 g, 28.3 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (5 g, 25.8 mmol) and sodium hydroxide (0.103 g, 2.58 mmol) in N,N-Dimethylformamide (DMF) (18 mL) was stirred at 140° C. for 16 h. then cooled to room temperature and treated with activated charcoal (200 mg). The resulting mixture was stirred at room temperature for 1 h then filtered through celite (10 g). The insoluble were washed with EtOAc (50 mL) and EtOH (50 mL). The combined filtrate and washings were concentrated in vacuo. Purification of the residue by flash chromatography on silica gel using a 50 G silica cartyridge (gradient: 0 to 40% MeOH in DCM) gave a residue which was further purified by SP4 using a 100 G silica cartridge (eluant: 0 to 20% MeOH in DCM) to give 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]ethanol (5.58 g, 23.44 mmol, 91% yield) as a colourless oil which was used in the next step without further purification.

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