Selenium Dioxide → 5,6,7,8-Tetrahydroisoquinoline-3-carbaldehyde

HRID 1637757Notes

Reaction equation

HRID 1637757 reaction equation
[OH:1][CH2:2][C:3]1[N:4]=[CH:5][C:6]2[CH2:7][CH2:8][CH2:9][CH2:10][C:11]=2[CH:12]=1.[Se](=O)=O>O1CCOCC1.ClCCl>[CH:5]1[C:6]2[CH2:7][CH2:8][CH2:9][CH2:10][C:11]=2[CH:12]=[C:3]([CH:2]=[O:1])[N:4]=1

Participants

5

Reactant 2

HCID 24007Selenium DioxideHCID 18799805(5,6,7,8-Tetrahydroisoquinolin-3-yl)methanol

Product 1

HCID 187995785,6,7,8-Tetrahydroisoquinoline-3-carbaldehydeYield 70.2%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
82.5 °C

Procedure

3-Hydroxymethyl-5,6,7,8-tetrahydroisoquinoline (1.73 g, 10.6 mmole) is dissolved in 30 ml dioxane in a 100 ml one neck round bottom flask under nitrogen. The solution is treated with selenium dioxide (647 mg, 5.8 mmole) and the reaction mixture is warmed to 80-85° C. for 1.5 h. The mixture is cooled to room temperature, is diluted with 30 ml dichloromethane and is filtered through celite. The filter cake is washed well with fresh dichloromethane and the filtrate is concentrated in vacuo to a dark amber oil. The crude material is chromatographed through a 25 g plug of silica gel (230-400 mesh), eluting with 20% acetone/hexane while collecting 50 ml fractions. Fractions 1-3 are combined and concentrated to give 1.20 g (70%) of 5,6,7,8,-tetrahydroisoquinoline-3-carbaldehyde.

Workup

  1. temperatureThe mixture is cooled to room temperature
  2. filtrationis filtered through celite
  3. washThe filter cake is washed well with fresh dichloromethane
  4. concentrationthe filtrate is concentrated in vacuo to a dark amber oil
  5. customThe crude material is chromatographed through a 25 g plug of silica gel (230-400 mesh)
  6. washeluting with 20% acetone/hexane
  7. customwhile collecting 50 ml fractions
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-a7aa482d3f8f473fb5e7daa429fc64f0
Source dataset
uspto-grants-2000_03
Patent number
US06043248

Reaction notes

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