Ethylene Glycol → 6-Bromospiro[2H-1-benzopyran-3(4H),2'-[1,3]dioxolane]

HRID 1408432Notes

Reaction equation

HRID 1408432 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][C:8](=[O:11])[CH2:7][C:6]=2[CH:12]=1.[CH2:13](O)[CH2:14][OH:15].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][C:8]3([O:15][CH2:14][CH2:13][O:11]3)[CH2:7][C:6]=2[CH:12]=1

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 584666226-bromo-3,4-dihydro-2H-1-benzopyran-3-one

Product 1

HCID 671512246-Bromospiro[2H-1-benzopyran-3(4H),2'-[1,3]dioxolane]Yield 94.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 6-bromo-2H-1-benzopyran-3(4H)-one (300 mg, 1.13 mmol) in toluene (2 mL) was added ethyleneglycol (163 mg 2.64 mmol) and para-toluenesulfonic acid (27 mg, 0.13 mmol). The reaction mixture was heated at 100° C. for 6 hrs. The reaction mixture was cooled and the solvent concentrated. The resultant residue was partitioned between ethyl acetate and water. The organic phase was washed with water, brine, dried over Na2SO4 and concentrated under vacuum to give the title compound (290 mg, 79% yield) as a solid.

Workup

  1. temperatureThe reaction mixture was cooled
  2. concentrationthe solvent concentrated
  3. customThe resultant residue was partitioned between ethyl acetate and water
  4. washThe organic phase was washed with water, brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-c80036f10e2745eda52e07e53243a9f5
Source dataset
uspto-grants-2014_12
Patent number
US08921360B2

Reaction notes

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