Selenium Dioxide → 5,6,7,8-Tetrahydroisoquinoline-1-carbaldehyde

HRID 1637762Notes

Reaction equation

HRID 1637762 reaction equation
[OH:1][CH2:2][C:3]1[C:12]2[CH2:11][CH2:10][CH2:9][CH2:8][C:7]=2[CH:6]=[CH:5][N:4]=1.[Se](=O)=O>O1CCOCC1.ClCCl>[C:3]1([CH:2]=[O:1])[C:12]2[CH2:11][CH2:10][CH2:9][CH2:8][C:7]=2[CH:6]=[CH:5][N:4]=1

Participants

5

Reactant 2

HCID 24007Selenium DioxideHCID 18799883HCID 18799883, compound

Product 1

HCID 187996715,6,7,8-Tetrahydroisoquinoline-1-carbaldehydeYield 90.1%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
82.5 °C

Procedure

1-Hydroxymethyl-5,6,7,8-tetrahydroisoquinoline (4.14 g, 25.4 mmole) is dissolved in 75 ml dioxane in a 200 ml one neck round bottom flask under nitrogen. The solution is treated with selenium dioxide (1.56 g, 14.0 mmole) and the reaction mixture is warmed to 80-85° C. for 2.5 h. The mixture is cooled to room temperature, is diluted with 125 ml dichloromethane and is filtered through celite. The filter cake is washed well with fresh dichloromethane and the filtrate is concentrated in vacuo to an amber oil. The crude material is chromatographed over 200 g silica gel (230-400 mesh), eluting with 1:5:4 acetone/chloroform/hexane while collecting 50 ml fractions. Fractions 11-18 are combined and concentrated to give 3.69 g (90%) of 5,6,7,8,-tetrahydroisoquinoline-1-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 an amber oil
  5. customThe crude material is chromatographed over 200 g silica gel (230-400 mesh)
  6. washeluting with 1:5:4 acetone/chloroform/hexane
  7. customwhile collecting 50 ml fractions
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-22fd1138cc7f449cae394525eaf34478
Source dataset
uspto-grants-2000_03
Patent number
US06043248

Reaction notes

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