2-Methoxynaphthalene → 2-Bromo-3-methoxynaphthalene

HRID 1504488Notes

Reaction equation

HRID 1504488 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=1.C([Li])CCC.[Br:18]CCBr.[OH-].[Na+]>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].C1COCC1>[Br:18][C:12]1[C:3]([O:2][CH3:1])=[CH:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:11]=1

Participants

7

Reactant 4

HCID 71192-MethoxynaphthaleneHCID 78391,2-DibromoethaneHCID 14798Sodium HydroxideHCID 178418339Butyllithium

Product 1

HCID 133519102-Bromo-3-methoxynaphthaleneYield 58.4%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A RBF was charged 2-methoxynaphthalene (2.00 g, 12.64 mmol) and THF (30 mL) to give a clear solution. n-butyllithium (2.5M in hexanes) (5.66 mL, 14.16 mmol) was added dropwise. The flask was cooled in a dry ice-acetone bath for 10 min and 1,2-dibromoethane (1.634 mL, 18.96 mmol) was added dropwise. The reaction was warmed to room temperature and stirred for 16 hours. NaOH (1 M, 10 mL, 10 mmol 0 was added and the reaction was heated to reflux for 1 hour. The mixture was cooled to room temperature and extracted with DCM (2×), and the combined organic extracts were dried over magnesium sulfate, filtered, and concentrated. The crude solid was recrystallized from heptane to give 2-bromo-3-methoxynaphthalene (1.75 g, 7.38 mmol, 58.4% yield) as an off-white solid. m/z (ESI) 237.1 (M+H)+.

Workup

  1. customto give a clear solution
  2. temperatureThe flask was cooled in a dry ice-acetone bath for 10 min
  3. temperaturethe reaction was heated
  4. temperatureto reflux for 1 hour
  5. temperatureThe mixture was cooled to room temperature
  6. extractionextracted with DCM (2×)
  7. dry with materialthe combined organic extracts were dried over magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe crude solid was recrystallized from heptane

Sources & evidence

ORD record
ord-f7dc892d457d434698b64d65e527b2d9
Source dataset
uspto-grants-2015_12
Patent number
US09212182B2

Reaction notes

Loading…