Ethylene Glycol → 2-Phenyl-2-(2-thienyl)-1,3-dioxolane

HRID 1262946Notes

Reaction equation

HRID 1262946 reaction equation
[C:1]([C:9]1[S:10][CH:11]=[CH:12][CH:13]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C1(C)C=CC=CC=1.[CH2:21](O)[CH2:22][OH:23]>C1(C)C=CC(S(O)(=O)=O)=CC=1>[C:2]1([C:1]2([C:9]3[S:10][CH:11]=[CH:12][CH:13]=3)[O:23][CH2:22][CH2:21][O:8]2)[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 174Ethylene Glycol2×HCID 1140TolueneHCID 672622-Benzoylthiophene

Product 1

HCID 129626732-Phenyl-2-(2-thienyl)-1,3-dioxolane

Reagents, catalysts & solvents 1

HCID 6101p-Toluenesulfonic acidCatalyst

Procedure

2-Benzoylthiophene (19 g., 0.1 mole), ethylene glycol (11 ml., 0.2 mole), toluene (150 ml.) and p-toluenesulfonic acid (about 0.2 g.) were combined and refluxed for 6 hours. By-product water was collected in a Dean-Stark trap. Tlc (1:8 ethyl acetate:hexane) indicated reaction to be about 40% complete. More ethylene glycol (30 ml.) was added and reflux continued for 35 hours. Reaction was still incomplete. The reaction mixture was diluted with 200 ml. of ether, washed twice with 150 ml. portions of water and concentrated to dryness. The residue was chromatographed on about 500 ml. of silica gel, with 1:8 ethyl acetate:hexane as eluant, monitored by tlc. Faster moving, product containing fractions were combined and evaporated to yield 2-phenyl-2-(2-thienyl)-1,3-dioxolane [8 g., oil, Rf 0.6 (1:8 ethyl acetate:hexane)].

Workup

  1. temperaturerefluxed for 6 hours
  2. customBy-product water was collected in a Dean-Stark trap
  3. customreaction
  4. temperaturereflux
  5. customReaction
  6. additionThe reaction mixture was diluted with 200 ml
  7. washof ether, washed twice with 150 ml
  8. concentrationportions of water and concentrated to dryness
  9. customThe residue was chromatographed on about 500 ml
  10. additionproduct containing fractions
  11. customevaporated

Sources & evidence

ORD record
ord-436da4dd285d4a1aae632fa3b7699d33
Source dataset
uspto-grants-1984_06
Patent number
US04454320

Reaction notes

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