Methyl iodide → 2-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2H-indazole

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Reaction Steps

A solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indazole (400 mg) in dry DMF (4 mL) precooled to 0° C. was added to a suspension of sodium hydride (80 mg) in dry THF (5 mL) at −78° C. under inert atmosphere. After 30 min, iodomethane (112 uL) was added to the mixture at −78° C. The reaction mixture was allowed slowly to warm up to room temperature overnight and then diluted with DCM, washed with brine, dried (MgSO4) and the solvent removed in vacuo. The residue was purified using flash chromatography to yield 1-methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indazole (143 mg) and 2-methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-2H-indazole (160 mg).

Provenance & Evidence