Bromine → 6-(Benzyloxy)-2-bromo-1,2,3,4-tetrahydronaphthalen-1-ol

HRID 2423680Notes

Reaction equation

HRID 2423680 reaction equation
[CH2:1]([O:8][C:9]1[CH:10]=[C:11]2[C:16](=[CH:17][CH:18]=1)[C:15](=[O:19])[CH2:14][CH2:13][CH2:12]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Br:20]Br>C(OCC)C>[CH2:1]([O:8][C:9]1[CH:10]=[C:11]2[C:16]([CH:15]=[C:14]([Br:20])[CH2:13][CH2:12]2)=[CH:17][CH:18]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:1]([O:8][C:9]1[CH:10]=[C:11]2[C:16](=[CH:17][CH:18]=1)[CH:15]([OH:19])[CH:14]([Br:20])[CH2:13][CH2:12]2)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 24408BromineHCID 106822416-(benzyloxy)-3,4-dihydronaphthalen-1(2H)-one

Product 2

HCID 230872486-(Benzyloxy)-2-bromo-1,2,3,4-tetrahydronaphthalen-1-olHCID 230874203-Bromo-1,2-dihydro-7-(phenylmethoxy)naphthalene

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

The title compound was synthesized by referring to J. Org. Chem., 1984, 49 (22), 4226. To a suspension of 6-benzyloxy-3,4-dihydro-2H-naphthalen-1-one (200 g) in diethyl ether (2 l) was added dropwise bromine (60 ml) on an ice bath, and the solution was stirred overnight at room temperature. The reaction mixture was poured into ice water, extracted with diethyl ether, then sequentially washed with a saturated aqueous solution of sodium bicarbonate, water and brine, dried over anhydrous magnesium sulfate, then filtered through NH silica gel, the solvent was evaporated in vacuo. To the resulting 6-benzyloxy-2-bromo-3,4-dihydro-2H-naphthalen-1-one (250 g) was added ethanol (2.5 l), the solution was stirred, sodium borohydride (25 g) was added thereto on an ice bath followed by stirring overnight at room temperature. The reaction mixture was poured into ice water, and the resulting solid was washed with water to provide 6-benzyloxy-2-bromo-1,2,3,4-tetrahydronaphthalen-1-ol (290 g). To a suspension of this compound (260 g) in toluene (800 ml) was added p-toluenesulfonic acid monohydrate (6.0 g), and the solution was refluxed for 2 hours. The reaction mixture was poured into ice water, extracted with ethyl acetate, then sequentially washed with water and brine, dried over anhydrous magnesium sulfate, then filtered through NH silica gel, and the solvent was evaporated in vacuo. The residue was purified by NH silica gel column chromatography (hexane-ethyl acetate system) to provide the title compound (34 g).

Workup

  1. extractionextracted with diethyl ether
  2. washsequentially washed with a saturated aqueous solution of sodium bicarbonate, water and brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. filtrationfiltered through NH silica gel
  5. customthe solvent was evaporated in vacuo
  6. additionTo the resulting 6-benzyloxy-2-bromo-3,4-dihydro-2H-naphthalen-1-one (250 g) was added ethanol (2.5 l)
  7. stirringthe solution was stirred
  8. additionsodium borohydride (25 g) was added
  9. customon an ice bath followed
  10. stirringby stirring overnight at room temperature
  11. additionThe reaction mixture was poured into ice water
  12. washthe resulting solid was washed with water

Sources & evidence

ORD record
ord-b9aa8e21865941719084b882f8036367
Source dataset
uspto-grants-2011_06
Patent number
US07960412B2

Reaction notes

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