Ethylene Glycol → 6-bromo-2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]

HRID 617695Notes

Reaction equation

HRID 617695 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:10][CH2:9][CH2:8][C:7](=[O:11])[C:6]=2[CH:12]=1.[CH2:13](O)[CH2:14][OH:15]>O.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[S:10][CH2:9][CH2:8][C:7]3([O:15][CH2:14][CH2:13][O:11]3)[C:6]=2[CH:12]=1

Participants

5

Reactant 2

HCID 174Ethylene GlycolHCID 139537366-Bromo-2,3-dihydro-4H-1-benzothiopyran-4-one

Product 1

HCID 218490186-bromo-2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]Yield 78.8%

Reagents, catalysts & solvents 2

HCID 521998p-Toluenesulfonic acid monohydrateCatalystHCID 1140TolueneSolvent

Procedure

14.7 g (0.060 mol) of the title compound of Step B, 11 mL (0.19 mol) of ethylene glycol (purchased from Aldrich Chemical Company), and 0.4 g (2.10 mmol) of p-toluenesulfonic acid monohydrate (purchased from Aldrich Chemical Company) were added to 125 mL of toluene. The solution was stirred at reflux under nitrogen overnight, and was then washed with 1M sodium carbonate (2×250 mL), followed by water (2×250 mL). The organic layer was dried (Na2SO4), filtered, and evaporated to dryness to yield 13.58 g of the title compound of Step C as an oil. 1H NMR (CDCl3): δ2.2 (m,2H), 3.16 (m,2H), 4.1 (m,2H), 4.2 (m,2H), 7.0-7.6 (3H).

Workup

  1. temperatureat reflux under nitrogen overnight
  2. washwas then washed with 1M sodium carbonate (2×250 mL)
  3. dry with materialThe organic layer was dried (Na2SO4)
  4. filtrationfiltered
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-56454dfac1fa490fa8a4d7f70b538678
Source dataset
uspto-grants-1999_09
Patent number
US05952266

Reaction notes

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