2-Methyl-5-vinylpyridine → 8-Isopropyl-2-methyl-5-[2-(6-methyl-pyridin-3-yl)-ethyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole

HRID 2195970Notes

Reaction equation

HRID 2195970 reaction equation
[CH:1]([C:4]1[CH:12]=[CH:11][C:10]2[NH:9][C:8]3[CH2:13][CH2:14][N:15]([CH3:17])[CH2:16][C:7]=3[C:6]=2[CH:5]=1)([CH3:3])[CH3:2].[OH-].[K+].[CH3:20][C:21]1[CH:26]=[CH:25][C:24]([CH:27]=[CH2:28])=[CH:23][N:22]=1>CN1CCCC1=O.O>[CH:1]([C:4]1[CH:12]=[CH:11][C:10]2[N:9]([CH2:28][CH2:27][C:24]3[CH:23]=[N:22][C:21]([CH3:20])=[CH:26][CH:25]=3)[C:8]3[CH2:13][CH2:14][N:15]([CH3:17])[CH2:16][C:7]=3[C:6]=2[CH:5]=1)([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 88172-Methyl-5-vinylpyridineHCID 14797Potassium HydroxideHCID 594552192,3,4,5-tetrahydro-8-isopropyl-2-methyl-1H-pyrido[4,3-b]indole

Product 1

HCID 578759068-Isopropyl-2-methyl-5-[2-(6-methyl-pyridin-3-yl)-ethyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoleYield 15%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 13387N-methyl-2-pyrrolidoneSolvent

Procedure

To a solution of 8-Isopropyl-2-methyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (0.2 g, 0.877 mmol) in N-methyl 2-pyrolidone (2 mL) was added powdered potassium hydroxide (0.2 g, 3.5 mmol) and allowed to stir for 10 min at RT. 2-methyl-5-vinyl pyridine (0.104 g, 0.877 mmol) was added and stirred for further at 120 deg C. for 20 h. Reaction mixture was diluted with water (30 mL) and extracted with ethyl acetate (3×50 mL). The organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The crude was purified through column chromatography (5% Me OH:DCM in silica 100-200 mesh, Diameter of column—2.5 cm, Height of silica—approx. 5 inch) and further purified with preparative TLC to provide the desired compound as brown oil (0.045 g, 15% yield). 8-Isopropyl-2-methyl-5-[2-(6-methyl-pyridin-3-yl)-ethyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (0.045 g, 0.129 mmol) was dissolved in THF (2.0 mL). A solution of oxalic acid dihydrate (0.016 g, 0.129 mmol) in THF (2 mL) was added and stirred for 30 min at RT, Precipitate obtained was filtered and dried to give oxalate salt as off white solid (0.045 g, 80% yield).

Workup

  1. stirringstirred for further at 120 deg C
  2. waitfor 20 h
  3. customReaction mixture
  4. extractionextracted with ethyl acetate (3×50 mL)
  5. dry with materialThe organic layer was dried over anhydrous sodium sulphate
  6. concentrationconcentrated under reduced pressure
  7. customThe crude was purified through column chromatography (5% Me OH:DCM in silica 100-200 mesh, Diameter of column—2.5 cm, Height of silica—approx. 5 inch)
  8. customfurther purified with preparative TLC

Sources & evidence

ORD record
ord-419d09f101834188a6da6a8e7cab519b
Source dataset
uspto-grants-2012_12
Patent number
US08338408B2

Reaction notes

Loading…