Potassium Hydroxide → 3,3-dimethyl-3,4-dihydroisoquinoline

HRID 2393762Notes

Reaction equation

HRID 2393762 reaction equation
[OH-].[K+].C1(C)C(S([N:12]2[C:21]([CH3:23])([CH3:22])[CH2:20][C:19]3[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=3)[CH2:13]2)(=O)=O)=CC=CC=1>CO>[CH3:22][C:21]1([CH3:23])[CH2:20][C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH:13]=[N:12]1

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 18977225HCID 18977225, compound

Product 1

HCID 110409823,3-dimethyl-3,4-dihydroisoquinolineYield 90%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a nitrogen-blanketed mixture of potassium hydroxide (KOH, 30 g) and methanol (CH3OH, 60 mL) was added of N-toluenesulfonyl-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (4.0 g, 0.013 mol.). The reaction mixture was heated at reflux for 17 hours and the reaction was followed by gas chromatography. The reaction mixture was cooled to ambient temperature, quenched with water (100 mL) and 10% HCl was slowly added until pH=7 was obtained. The aqueous mixture was extracted with methylene chloride (3×100 mL) and the organic layers were combined and stirred with charcoal and sodium sulfate (Na2 SO4). The solution was filtered through celite and the filtrate was concentrated (25°/150 torr) to give 3,3-dimethyl-3,4-dihydroisoquinoline (1.79 g, yield=90%).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 17 hours
  3. customquenched with water (100 mL) and 10% HCl
  4. additionwas slowly added until pH=7
  5. customwas obtained
  6. extractionThe aqueous mixture was extracted with methylene chloride (3×100 mL)
  7. filtrationThe solution was filtered through celite
  8. concentrationthe filtrate was concentrated (25°/150 torr)

Sources & evidence

ORD record
ord-cfb4ba39b8be4522a3697d04ebf8f1bf
Source dataset
uspto-grants-1998_09
Patent number
US05808071

Reaction notes

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