Hexane → 4-(2-Methoxyethyl)-1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

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Reaction Steps

To a solution of 4-(2-methoxyethyl)-1-methyl-1H-pyrazole (0.400 g, 2.85 mmol) in tetrahydrofuran (10 mL) at 0° C. was added 1.6 M n-butyllithium in hexane (6.24 mL, 9.99 mmol). The solution was stirred at room temperature for 1 h and then cooled down to −78° C. To the solution was added 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.70 mL, 3.4 mmol). The reaction was continued at −78° C. for 0.5 h, then warmed up to 0° C. (taking 0.5 h). The reaction mixture was quenched with brine, adjusted to pH=6-7 with 1 N HCl aqueous solution, and extracted with EtOAc (2×). The combined organic phases were washed with brine, dried over Na2SO4, and concentrated to give a brown oil which was further purified to provide 0.33 g (43% yield) of the desired product. LC-MS found: 267.1 (M+H)+.

Provenance & Evidence