Dimethyl Sulfate → 5-Bromo-2-methyl-8-nitro-1,2,3,4-tetrahydroisoquinoline

HRID 736437Notes

Reaction equation

HRID 736437 reaction equation
[Br:1][C:2]1[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[C:8]2[C:3]=1[CH:4]=[CH:5][N:6]=[CH:7]2.[CH3:15]OS(OC)(=O)=O.[BH4-].[Na+]>C(O)(=O)C>[Br:1][C:2]1[CH:11]=[CH:10][C:9]([N+:12]([O-:14])=[O:13])=[C:8]2[C:3]=1[CH2:4][CH2:5][N:6]([CH3:15])[CH2:7]2

Participants

5

Reactant 3

HCID 6497Dimethyl SulfateHCID 8169835-Bromo-8-nitroisoquinolineHCID 4311764Sodium borohydride

Product 1

HCID 100160105-Bromo-2-methyl-8-nitro-1,2,3,4-tetrahydroisoquinoline

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

5-Bromo-8-nitroisoquinoline (216.9 g, 0.86 mol) was added in portions during 10 min to a solution of dimethylsulphate (750 ml). Some heat was developed. The mixture was heated at 100° C. for 10 minutes. 5-Bromo-2-methyl-8-nitroquinolinium methyl sulphate precipitated. The mixture was cooled on ice and diethyl ether (1 l) was added. The crude mixture was filtered and crystals were isolated. The salt was solved in acetic acid (1.5 l). To the ice-cooled mixture was added: sodium borohydride (47 g, 1.24 mol) over 4 hours. The temperature was kept below 30° C. The crude mixture was evaporated and sodium hydroxide (2 l, 1 M) was added. The crystals were filtered. Yield 205.2 g (88%). Mp 85-87° C.

Workup

  1. custom5-Bromo-2-methyl-8-nitroquinolinium methyl sulphate precipitated
  2. temperatureThe mixture was cooled on ice and diethyl ether (1 l)
  3. additionwas added
  4. filtrationThe crude mixture was filtered
  5. customcrystals were isolated
  6. additionwas added
  7. customwas kept below 30° C
  8. customThe crude mixture was evaporated
  9. additionsodium hydroxide (2 l, 1 M) was added
  10. filtrationThe crystals were filtered

Sources & evidence

ORD record
ord-25e3c17d6d7d46fa8262b64add1cec4c
Source dataset
uspto-grants-2009_09
Patent number
US07595336B2

Reaction notes

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