Phosphorus oxychloride → 3-formyl-N-pentenyl-carbazole

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (9.1 g, 60mmol) was added to dimethylformamide (17 mL) at 0° C. with strong stirring over 15 minutes. Upon complete addition, the orange solution was stirred at 0° C. for a further 10 minutes. N-pentenyl-carbazole (10.5 g, 45 mmol) was gradually added to the iminium salt and the mixture was heated at 100° C. for 1.5 hours, then cooled to room temperature and added to ice. The ice slurry was adjusted to a pH of 6 with saturated sodium acetate solution and the crude product was extracted with dichloromethane (2×50 mL), dried (Na2SO4), and concentrated. Traces of dimethylformamide were removed under high vacuum to give 9.6 g of 3-formyl-N-pentenyl-carbazole as a brown oil. The material was used at this level of purity in the next step of the synthesis.

Provenance & Evidence