Triphenylphosphine → 4-(2-Morpholin-4-ylethoxy)benzeneboronic acid, pinacol ester

Participants

Reaction Steps

To a stirring solution of 4-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-phenol (2.55 g, 11.58 mmol), 2-morpholin-4-ylethanol (1.60 mL, 1.73 g, 13.2 mmol) and triphenyl phosphine (3.64 g, 13.9 mmol) in methylene chloride (60 mL) at 0° C. was added dropwise DIAD (2.82 g, 13.9 mmol). The reaction was allowed to warm to room temperature and stir overnight. After 18 hours, additional portions of triphenyl phosphine (1.51 g, 5.8 mmol), 2-morpholin-4-ylethanol (0.70 mL, 5.8 mmol), and DIAD (1.17 g, 5.8 mmol) were added. After stirring an additional 2 hours at room temperature the reaction was concentrated and the residue purified by flash chromatography (5% to 25% EtOAc in CHCl3) to provide the product as a white solid (2.855 g, 74%).

Provenance & Evidence