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

HRID 717793Notes

Reaction equation

HRID 717793 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[NH:9]N.[CH3:11][N:12]1[CH2:17][CH2:16][C:15](=O)[CH2:14][CH2:13]1>OS(O)(=O)=O.O1CCOCC1>[Br:1][C:2]1[C:3]2[NH:9][C:15]3[CH2:16][CH2:17][N:12]([CH3:11])[CH2:13][C:14]=3[C:4]=2[CH:5]=[C:6]([CH3:8])[CH:7]=1

Participants

5

Reactant 2

HCID 740491-Methyl-4-piperidoneHCID 292001(2-Bromo-4-methylphenyl)hydrazine

Product 1

HCID 673765326-bromo-2,8-dimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoleYield 69.6%

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
80 °C

Procedure

(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).

Workup

  1. customAfter completion of the reaction
  2. customthe dioxane was evaporated under reduced pressure
  3. extractionextracted with EtOAc
  4. customThe organic layer was evaporated under reduced pressure
  5. customThe crude product was crystallized from hexane and diethyl ether

Sources & evidence

ORD record
ord-c74d18c94e3148159f62eb2521398fad
Source dataset
uspto-grants-2015_11
Patent number
US09193728B2

Reaction notes

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