Pyridine → 2-chloro-1-phenyl-1H-indole-3-carbaldehyde

Participants

Reaction Steps

A mixture of 2-chloro-1H-indole-3-carboxaldehyde (5.00 g, 27.8 mmol), phenylboronic acid (6.79 g, 55.6 mmol), cupric acetate (10.11 g, 55.7 mmol), pyridine (4.40 g, 55.7 mmol), triethylamine (5.63 g, 55.6 mmol), 4 Å molecular sieves (15.0 g) dichloromethane (300 mL) is stirred at room temperature for 4 d. The reaction mixture is filtered through a pad of Celite and the filtrate is washed with water, with 2N aq hydrochloric acid, with sat aq sodium bicarbonate, with brine, dried, filtered and concentrated. The residue is purified by chromatography eluting with dichloromethane. Product containing fractions are combined and concentrated to afford 2-chloro-1-phenyl-1H-indole-3-carboxaldehyde (4.40 g, 88% yield) as a yellow solid. NMR (CDCl3) 12.30 (1H, s), 8.37 (1H, d), 7.58-7.70 (3H, m), 7.43 (2H, d), 7.23-7.40 (2H, m), 7.10 (1H, d).

Provenance & Evidence