1-Hydroxybenzotriazole → [4-(Pyrrolidin-1-yl)piperidin-1-yl][4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]methanone

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Reaction Steps

A solution of 4-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)benzoic acid (9.80 mmol, 2.43 g), 4-(1-pyrrolidinyl)piperidine (10.77 mol, 1.66 g), 1-hydroxybenzotriazole (16.67 mmol, 2.25 g), and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (19.57 mmol, 3.75 g) in DMF (30 mL) was stirred overnight at 60° C. Upon removal of DMF on rotavap, the residue was taken into mixture of EtOAc and H2O. The combined organic layers from extraction were stirred with aq. 2N HCl for 20 min and the aqueous layer was purified by reverse phase prep-HPLC to furnish the desired boronic acid (1.24 g. 42%).

Provenance & Evidence