p-Toluenesulfonyl isocyanate → 4-{2-[({[(4-Methylphenyl)sulfonyl]amino]carbonyl)oxy]ethyl}phenylboronic acid

Participants

Reaction Steps

4-(2-Hydroxyethyl)phenylboronic acid (step 1, 1.00 g, 6.02 mmol) was treated with pyridine (90 mL) and p-toluenesulfonylisocyanate (1.01 mL, 6.63 mmol) at room temperature for 2 h. The mixture was poured into ice-2 M HCl (200 mL) and extracted with ethyl acetate, (300 mL), and the organic fraction was dried (MgSO4). After removal of solvent, the residue was purified by silica-gel column chromatography eluting with dichloromethane/methanol (20:1) to give 2.20 g (quant.) of the title compound as white solids: MS (ESI) m/z 381 [M+NH4]+, 362 [M−H]−, 1H-NMR (DMSO-d6) δ 11.95 (1H, br.s), 7.97 (1H, s), 7.75-7.67 (2H, m), 7.40 (2H, d, J=8.6 Hz), 7.13 (2H, d, J=7.7 Hz), 4.18 (2H, t, J=6.6 Hz), 2.81 (2H, t, J=6.6 Hz), 2.40 (3H, s).

Provenance & Evidence