Ethylene Glycol → 5'-bromo-3',4'-dihydro-1'H-spiro[[1,3]-dioxolane-2,2'-naphthalene]

HRID 1423381Notes

Reaction equation

HRID 1423381 reaction equation
[CH2:1]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6](C=O)[C:5]=2[CH2:4][CH2:3][C:2]21[O:16][CH2:15][CH2:14][O:13]2.[Br:17]C1C=CC=C2C=1CCC(=O)C2.C(O)CO.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1.CCOCC>[Br:17][C:6]1[CH:7]=[CH:8][CH:9]=[C:10]2[C:5]=1[CH2:4][CH2:3][C:2]1([O:16][CH2:15][CH2:14][O:13]1)[CH2:1]2

Participants

7

Reactant 4

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 40596895-Bromo-2-tetraloneHCID 866887243',4'-Dihydro-1'H-spiro[[1,3]dioxolane-2,2'-naphthalene]-5'-carbaldehyde

Product 1

HCID 866887235'-bromo-3',4'-dihydro-1'H-spiro[[1,3]-dioxolane-2,2'-naphthalene]Yield 98%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 3283Diethyl EtherSolvent

Procedure

3′,4′-Dihydro-1′H-spiro[[1,3]dioxolane-2,2′-naphthalene]-5′-carbaldehyde, designated as 37 in FIG. 15, was prepared as follows: A solution of 5-bromo-3,4-dihydronaphthalen-2(1H)-one (625 mg, 2.78 mmol), ethylene glycol (0.23 mL, 4.17 mmol), and p-toluenesulfonic acid (5.70 mg, 0.03 mol) in benzene (46 mL) was stirred and heated to reflux for 10 h. The solution was cooled, diluted with ether, and sequentially washed with saturated aqueous sodium bicarbonate solution and water. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by silica gel column chromatography, using a 2:1 mixture of hexanes and AcOEt as eluant, furnished 5′-bromo-3′,4′-dihydro-1′H-spiro[[1,3]-dioxolane-2,2′-naphthalene](730.4 mg, 98% yield) as a yellow oil. Yield: 65%.

Workup

  1. customwas prepared
  2. temperatureheated
  3. temperatureto reflux for 10 h
  4. temperatureThe solution was cooled
  5. washsequentially washed with saturated aqueous sodium bicarbonate solution and water
  6. dry with materialThe organic layer was dried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customPurification by silica gel column chromatography
  10. additiona 2:1 mixture of hexanes and AcOEt as eluant

Sources & evidence

ORD record
ord-cb4ce1ff52c44fddbe565c998b020cf8
Source dataset
uspto-grants-2015_01
Patent number
US08927586B2

Reaction notes

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