4-(Trifluoromethoxy)phenylhydrazine hydrochloride → 2-methyl-8-trifluoromethoxy-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole

Participants

Reaction Conditions

Reaction Steps

(4-(Trifluoromethoxy)phenyl)hydrazine hydrochloride (1 g, 4.37 mmol) was dissolved in 7% H2SO4 in 1,4-dioxane (50 mL), 1-methylpiperidin-4-one hydrochloride (0.65 g, 4.37 mmol) was added and stirred at 80° C. for 6 h. Reaction was monitored by TLC & LCMS. After completion of the reaction, reaction mixture was concentrated under vacuum and slowly quenched with aq. NaHCO3 solution, extracted with EtOAc. Organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure and purified by column chromatography to afford 0.9 g of 2-methyl-8-(trifluoromethoxy)-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole. 1H NMR (CDCl3, free base) δ (ppm) 7.9 (bs, 1H), 7.3-7.2 (m, 2H), 7.1-6.9 (d, 1H), 3.7 (s, 2H), 2.9-2.8 (m, 4H), 2.6 (s, 3H).

Provenance & Evidence