Dimethyl Sulfate → 5-Methoxy-1,2-dihydroisoquinolin-1-one

HRID 1645907Notes

Reaction equation

HRID 1645907 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[C:7]([OH:12])[CH:8]=[CH:9][CH:10]=2)[CH:5]=[CH:4][N:3]=1.[OH-].[Na+].S(OC)(O[CH3:19])(=O)=O>CO.O>[CH3:19][O:12][C:7]1[CH:8]=[CH:9][CH:10]=[C:11]2[C:6]=1[CH:5]=[CH:4][NH:3][C:2]2=[O:1]

Participants

6

Reactant 3

HCID 6497Dimethyl Sulfate2×HCID 14798Sodium Hydroxide2×HCID 178515888HCID 178515888, compound

Product 1

HCID 9288205-Methoxy-1,2-dihydroisoquinolin-1-oneYield 64%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent2×

Procedure

To 3.0 g (18.6 mmol) of 1,5-dihydroxyisoquinoline in 80 ml methanol and 20 ml of water was added 0.78 g of 50% sodium hydroxide (39 mmol) and 2 ml of dimethyl sulfate. The mixture was heated under reflux for two hours. An additional 4.0 ml of dimethyl sulfate and 10 ml of 50% sodium hydroxide was then added and refluxing continued for an additional hour. The mixture was diluted with 200 ml of water and concentrated to half the original volume. The resulting solid was collected and washed with water. Recrystallization from ethanol gave 2.1 g (64%) of the desired product; mp 215°-217°.

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux for two hours
  3. temperaturerefluxing
  4. waitcontinued for an additional hour
  5. concentrationconcentrated to half the original volume
  6. customThe resulting solid was collected
  7. washwashed with water
  8. customRecrystallization from ethanol

Sources & evidence

ORD record
ord-5b6a09e968b7458f92ea7d7e39092a45
Source dataset
uspto-grants-1993_01
Patent number
US05177075

Reaction notes

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