Ammonium Chloride → 4-(3-Bromopropyl)-6-methoxy-1,2-dihydronaphthalene

HRID 1978004Notes

Reaction equation

HRID 1978004 reaction equation
[Mg].[Br:2][CH:3]1[CH2:5][CH2:4]1.[CH3:6][O:7][C:8]1[CH:17]=[C:16]2[C:11]([CH2:12][CH2:13][CH2:14][C:15]2=O)=[CH:10][CH:9]=1.[Cl-].[NH4+]>C1COCC1>[Br:2][CH2:3][CH2:4][CH2:5][C:15]1[C:16]2[C:11](=[CH:10][CH:9]=[C:8]([O:7][CH3:6])[CH:17]=2)[CH2:12][CH2:13][CH:14]=1

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 78037BromocyclopropaneHCID 812767-Methoxy-1,2,3,4-tetrahydronaphthalen-1-oneHCID 5462224Magnesium

Product 1

HCID 104238234-(3-Bromopropyl)-6-methoxy-1,2-dihydronaphthaleneYield 597.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a suspension of magnesium (2.9 g) in THF (100 ml) was added bromocyclopropane (14.4 g, 11.9 mmol) dropwise at 0° C. under argon atmosphere. The mixture was stirred for 30 minutes at room temperature and then a solution of 7-methoxy-1-tetralone (15 g, 85.1 mmol) in THF (50 ml) was added. The mixture was refluxed for 2 hours and then cooled. Saturated aqueous ammonium chloride was introduced and the product was extracted with ethyl acetate. The extract was washed with brine and water, dried over anhydrous magnesium sulfate, and the solvent was removed in vacuo. The residue was dissolved in acetic acid (100 ml) and 20% hydrobromic acid (75 ml) was added. The mixture was stirred for 15 hours at room temperature and then concentrated. To the residue was added saturated aqueous sodium hydrogen bicarbonate and the product was extracted with ethyl acetate. The extract was washed with brine and water, dried over anhydrous magnesium sulfate, and the solvent removed in vacuo. The residue was purified by a silica gel column chromatography (ethyl acetate:hexane=1:9) to afford the titled compound (20 g, yield 84%, oil).

Workup

  1. temperatureThe mixture was refluxed for 2 hours
  2. temperaturecooled
  3. extractionthe product was extracted with ethyl acetate
  4. washThe extract was washed with brine and water
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customthe solvent was removed in vacuo
  7. dissolutionThe residue was dissolved in acetic acid (100 ml)
  8. addition20% hydrobromic acid (75 ml) was added
  9. stirringThe mixture was stirred for 15 hours at room temperature
  10. concentrationconcentrated
  11. additionTo the residue was added saturated aqueous sodium hydrogen bicarbonate
  12. extractionthe product was extracted with ethyl acetate
  13. washThe extract was washed with brine and water
  14. dry with materialdried over anhydrous magnesium sulfate
  15. customthe solvent removed in vacuo
  16. customThe residue was purified by a silica gel column chromatography (ethyl acetate:hexane=1:9)

Sources & evidence

ORD record
ord-2487f3f84d0f48a39c4b11668578d41d
Source dataset
uspto-grants-2001_05
Patent number
US06235789B1

Reaction notes

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