1-Methyl-4-piperidone → 6-bromo-2,8-dimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole

Participants

Reaction Conditions

Reaction Steps

(2-Bromo-4-methylphenyl)hydrazine (21.5 g, 0.107 mol) and 1-methylpiperidin-4-one (12.5 mL, 0.107 mol) was dissolved in 7% H2SO4 in 1,4-dioxane (150 mL) and stirred at 80° C. for 90 min. The reaction was monitored by TLC. After completion of the reaction, the dioxane was evaporated under reduced pressure, and the residue basified with aq. NaHCO3 solution, and extracted with EtOAc. The organic layer was evaporated under reduced pressure. The crude product was crystallized from hexane and diethyl ether to afford 20.8 g of 6-bromo-2,8-dimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole. 1H NMR (CDCl3) d (ppm): 10.9 (s, 1H), 7.20 (s, 1H), 7.10 (s, 1H), 3.50 (s, 2H), 2.90-2.80 (t, 2H), 2.70-2.60 (t, 2H), 2.40 (s, 3H), 2.30 (s, 3H).

Provenance & Evidence