Triethylamine → 4-(1,1-Dioxido-2-isothiazolidinyl)phenylboronic Acid Pinacol Ester

Participants

Reaction Conditions

Reaction Steps

4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (5 g, 22.8 mmol) was dissolved in DCM (100 mL, 0.2M), triethylamine (15 mL, 5.0 molar equivalent) was added to the mixture. The reaction was stirred at 0° C. for 5 min. 3-chloropropane-1-sulfonyl chloride (4.2 g, 23.0 mmol) was added portion wise. The reaction was stirred at 0° C. for 1 hr and brought gradually to room temperature, heated to reflux at 70° C. for 2 hr. The mixture was cooled to room temperature, diluted with EtOAc and water. The organic layer was washed with brine, dried over MgSO4, filtered, and concentrated. The residue was purified through a silica column to afford 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]isothiazolidine 1,1-dioxide as off-white solid (5.2 g, 70% yield). 1H NMR (400 MHz, DMSO-d6) δ 7.62 (d, 2H), 7.18 (d, 2H), 3.76 (t, 2H), 3.53 (t, 2H), 2.41 (t, 2H), 1.28 (s, 12H).

Provenance & Evidence