1,2,3,4-Tetrahydroisoquinoline → 3,4-Dihydroisoquinoline

HRID 1005674Notes

Reaction equation

HRID 1005674 reaction equation
[CH2:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][NH:2]1.BrN1C(=O)CCC1=O.[OH-].[Na+]>C(Cl)Cl>[CH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][N:2]=1

Participants

5

Reactant 3

HCID 70461,2,3,4-TetrahydroisoquinolineHCID 14798Sodium HydroxideHCID 67184N-bromobutanimide

Product 1

HCID 767053,4-DihydroisoquinolineYield 82%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 26.67 g (0.2 mol) of 1,2,3,4-tetrahydroisoquinoline in methylene chloride (300 ml) was added N-bromosuccinimide (39.2 g) under ice-cooling over 20 minutes. After stirring for 40 minutes, 30% sodium hydroxide aqueous solution (130 ml) was added to the reaction mixture. The organic layer was washed with water, extracted with 10% hydrochloric acid (200 ml), and the aqueous layer was washed with methylene chloride. The aqueous layer was basified with an aqueous ammonia, extracted with methylene chloride. The extract was dried over magnesium sulfate and then evaporated. The resulting residue was distilled (about 16 mm-Hg, 120 degrees), to give 21.5 g of the title compound as an oil.

Workup

  1. temperaturecooling over 20 minutes
  2. washThe organic layer was washed with water
  3. extractionextracted with 10% hydrochloric acid (200 ml)
  4. washthe aqueous layer was washed with methylene chloride
  5. extractionextracted with methylene chloride
  6. dry with materialThe extract was dried over magnesium sulfate
  7. customevaporated
  8. distillationThe resulting residue was distilled (about 16 mm-Hg, 120 degrees)

Sources & evidence

ORD record
ord-ed699eca2e824e6294a71d3ba91b1351
Source dataset
uspto-grants-2004_09
Patent number
US06787534B2

Reaction notes

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