Sulfuric Acid → 8-chloro-2-methyl-1H,2H,3H,4H,5H-pyrido(4,3-b)indole

Participants

Reaction Steps

Sulfuric acid (3.5 mL) was added to a solution of 4-chlorophenylhydrazine hydrochloride (2.0 g, 11.2 mmol) in dioxane (50 mL), and stirred for 5 min. at RT. N-methyl piperidone (0.76-1.4 equiv.) was added and the mixture was heated at 80° C. for 2 h. After reaction completion as determined by thin layer chromatography (TLC), the reaction mixture was concentrated to approximately 20 mL under reduced pressure and basified to pH 10 using a 10% aqueous KOH solution. The reaction product was extracted with EtOAc (3×50 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure using a rotary evaporator to obtain the product (1.3 g) as a brown solid. 1H NMR (CDCl3, freebase) δ (ppm): 7.40 (s, 1H), 7.20-7.10 (d, 1H), 7.10-7.00 (d, 1H), 3.60 (s, 2H), 2.90 (s, 4H), 2.60 (s, 3H).

Provenance & Evidence