Dimethylformamide → N-heptyl-3,6-Diformylcarbazole

Participants

Reaction Steps

As a specific example, in one embodiment, a 271 ml quantity of DMF (3.5 mol) can be added to a 1-liter, 3-neck round bottom flask equipped with mechanical stirrer, thermometer, and addition funnel. The contents can be cooled in a salt/ice bath. When the temperature inside the flask reached 0° C., 326 ml of POCl3 (3.5 mol) can be slowly added. During the addition of POCl3, the temperature inside the flask is not allowed to rise above 5° C. After the addition of POCl3 is completed, the reaction mixture can be allowed to warm to room temperature. A 126 g quantity of N-heptylcarbazole can be then added, and the flask can be heated to 90° C. for 24 hr. using a heating mantle. The reaction mixture can be cooled to room temperature, and the solution can be added slowly to a 4.5 liter beaker containing a solution of 820 g sodium acetate dissolved in 2 liters of water. The beaker can be cooled in an ice bath and stirred for 3 hr. The brownish solid obtained can be filtered and washed repeatedly with water, followed by a small amount of ethanol (50 ml). For a N-heptyl carbozole starting material, the resulting product was recrystallized once from toluene using activated charcoal and dried under vacuum in an oven heated at 70° C. for 6 hr to obtain 80 g (51% yield) of N-heptyl-3,6-diformyl-carbazole.

Provenance & Evidence