Ethylene Glycol → 1,3-Dioxolane, 2-(3-bromo-4-fluorophenyl)-

HRID 414304Notes

Reaction equation

HRID 414304 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[F:10])[CH:5]=[O:6].[CH2:11](O)[CH2:12][OH:13]>C1(C)C=CC(S(O)(=O)=O)=CC=1.C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]([CH:5]2[O:13][CH2:12][CH2:11][O:6]2)[CH:7]=[CH:8][C:9]=1[F:10]

Participants

5

Reactant 2

HCID 174Ethylene GlycolHCID 1736043-Bromo-4-fluorobenzaldehyde

Product 1

HCID 109777651,3-Dioxolane, 2-(3-bromo-4-fluorophenyl)-Yield 78.3%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Procedure

A mixture of 3-bromo-4-fluorobenzaldehyde (45.7 g), ethylene glycol (27.93 g), p-toluenesulphonic acid (0.225 g) and dry toluene (110 cm3) was heated at the reflux temperature under a Dean and Stark trap. After 4.5 hours, approximately 12 cm3 of water had collected in the trap, and analysis of the reaction mixture by gas liquid chromatography indicated that no starting aldehyde was present. The mixture was cooled and poured into diethyl ether, washed with saturated sodium bicarbonate solution and brine, and dried over anhydrous magnesium sulphate. Evaporation of the solvent under reduced pressure gave a yellow oil, which was purified by distillation under reduced pressure to give 2-(3-bromo-4-fluorophenyl)-1,3-dioxolane (43.56 g), boiling point 68°-106° C. at 0.004 mmHg.

Workup

  1. temperaturewas heated at the reflux temperature under a Dean and Stark trap
  2. customapproximately 12 cm3 of water had collected in the trap, and analysis of the reaction mixture by gas liquid chromatography
  3. temperatureThe mixture was cooled
  4. additionpoured into diethyl ether
  5. washwashed with saturated sodium bicarbonate solution and brine
  6. dry with materialdried over anhydrous magnesium sulphate
  7. customEvaporation of the solvent under reduced pressure
  8. customgave a yellow oil, which
  9. distillationwas purified by distillation under reduced pressure

Sources & evidence

ORD record
ord-2646390a0c8444219b9844c493b74f18
Source dataset
uspto-grants-1988_12
Patent number
US04791139

Reaction notes

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