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

HRID 1401410Notes

Reaction equation

Cl.[F:2][C:3]([F:14])([F:13])[O:4][C:5]1[CH:10]=[CH:9][C:8]([NH:11]N)=[CH:7][CH:6]=1.Cl.[CH3:16][N:17]1[CH2:22][CH2:21][C:20](=O)[CH2:19][CH2:18]1>OS(O)(=O)=O.O1CCOCC1>[CH3:16][N:17]1[CH2:22][CH2:21][C:20]2[NH:11][C:8]3[CH:7]=[CH:6][C:5]([O:4][C:3]([F:14])([F:13])[F:2])=[CH:10][C:9]=3[C:19]=2[CH2:18]1

Participants

Conditions

Temperature: 80 °C

Procedure

(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).

Workup

customReaction
customAfter completion of the reaction, reaction mixture
concentrationwas concentrated under vacuum
customslowly quenched with aq. NaHCO3 solution
extractionextracted with EtOAc
dry with materialOrganic layer was dried over anhydrous sodium sulfate
concentrationconcentrated under reduced pressure
custompurified by column chromatography

Sources & evidence

ORD record: ord-d07e2f6104d4425d9120b471521a8845
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08907097B2

Reaction notes

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