Phosphorus oxychloride → 9-(6-(Carbazol-9-yl)pyridine-2-yl)carbazole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of 2,6-di(carbazol-9-yl)pyridine, prepared above in step 1, (10.0 g, 24.4 mmol) in 1,2-dichloroethane (80.0 ml) was slowly added POCl3/DMF (32.0 g/16.0 g). POCl3/DMF was made by the addition of POCl3 into DMF at 0° C. at room temperature under nitrogen atmosphere and stirring. After the addition of POCl3/DMF, the reaction mixture was heated to 110° C. and kept at this temperature for 72 hours. After cooling, the reaction mixture was slowly added into an ice-bath cooled KOH water solution (500.0 ml of water with 100 g of KOH). After addition, the reaction mixture was stirred for 60 minutes. The water solution was extracted with ethyl acetate (3×100 ml). The organic extracted solution was washed with water until a pH=7 was obtained. The removal of solvent, crude product was purified by silica gel column with dichloromethane:hexanes:ethyl acetate (5:4.5:0.5) as the solvent mixture. After removal of the solvent mixture, the product was recrystallized from THF/water to give 4.3 g (40.3%) of pure product.

Provenance & Evidence