Benzyl Bromide → 7-(Benzyloxy)-3,4-dihydronaphthalen-1(2H)-one

HRID 2189966Notes

Reaction equation

HRID 2189966 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][CH2:8][C:9]2=[O:12])=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>CN(C=O)C>[CH2:19]([O:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][CH2:8][C:9]2=[O:12])=[CH:4][CH:3]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 5718187-hydroxy-3,4-dihydro-2H-naphthalen-1-one

Product 1

HCID 140682207-(Benzyloxy)-3,4-dihydronaphthalen-1(2H)-oneYield 90.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a suspension of 7-hydroxy-1-tetralone (1.0 g, 0.0061 mol) and K2CO3 (5.5 g) in DMF (20 mL) under an argon atmosphere was added benzyl bromide (0.725 mL, 0.0061 mol) at room temperature. The reaction mixture was then stirred at room temperature for 18 h before being poured onto ice. The aqueous solution was extracted with ethyl acetate, washed with water, dried over anhydrous Na2SO4, filtered and concentrated. The residue was purified by column chromatography on silica gel using ethyl acetate-hexane (15%) as eluent to give compound 7-benzyloxy-1-tetralone (1.395 g, 90%): thick oil, 1H NMR (500 MHz, CDCl3): δ 2.09-2.14 (m, 2H), 2.63 (d, J=6.5 Hz, 2H), 2.90 (d, J=6.0 Hz, 2H), 5.75 (s, 2H), 7.11-7.13 (dd, J=3.0 and 8.5 Hz, 1H), 7.17 (d, J=8.5 Hz, 1H), 7.31-7.45 (m, 5H), 7.62 (d, J=3.0 Hz, 1H). HFABMS m/z 253.1231 (calc for C17H16O2, MH+, 253.1229).

Workup

  1. additionbefore being poured onto ice
  2. extractionThe aqueous solution was extracted with ethyl acetate
  3. washwashed with water
  4. dry with materialdried over anhydrous Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe residue was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-8708c41bc4e54e93b27d0122572c17e1
Source dataset
uspto-grants-2012_12
Patent number
US08324262B2

Reaction notes

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