Ethylene Glycol → 2-(2-Bromo-5-fluorophenyl)-2-methyl-1,3-dioxolane

HRID 1764934Notes

Reaction equation

HRID 1764934 reaction equation
[CH2:1]([OH:4])[CH2:2][OH:3].C1(C)C=CC(S(O)(=O)=O)=CC=1.[Br:16][C:17]1[CH:22]=[CH:21][C:20]([F:23])=[CH:19][C:18]=1[C:24](=O)[CH3:25].C([O-])(O)=O.[Na+]>C1C=CC=CC=1.O>[Br:16][C:17]1[CH:22]=[CH:21][C:20]([F:23])=[CH:19][C:18]=1[C:24]1([CH3:25])[O:4][CH2:1][CH2:2][O:3]1

Participants

7

Reactant 4

HCID 174Ethylene GlycolHCID 6101p-Toluenesulfonic acidHCID 516892Sodium BicarbonateHCID 227360801-(2-Bromo-5-fluorophenyl)ethan-1-one

Product 1

HCID 227359282-(2-Bromo-5-fluorophenyl)-2-methyl-1,3-dioxolaneYield 60.2%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 962WaterSolvent

Procedure

Ethylene glycol (25.6 mL, 458 mmol) and p-toluenesulfonic acid (4.36 g, 22.9 g) were added to a solution of 1-(2-bromo-5-fluorophenyl)ethanone (10.5 g, 45.8 mmol) stirring in benzene (250 mL). The reaction mixture was equipped with a Dean Stark trap containing 4.0 angstrom molecular sieves and refluxed for 16 h. The reaction was transferred to a separatory funnel containing a 1:1 mixture of H2O and sat. NaHCO3 (aq) and extracted with EtOAc (3×100 mL). The combined organics were washed with H2O, brine, dried over Na2SO4 and concentrated. The resulting oil was purified by column chromatography to give 2-(2-bromo-5-fluorophenyl)-2-methyl-1,3-dioxolane (7.20 g) in 58% yield. 1H NMR (CDCl3, 300 MHz) δ2.60 (s, 3 H) 4.02-4.20 (m, 4H), 6.85-6.90 (m, 1H), 7.29-7.33 (m, 1H), 7.48-7.56 (m, 1H).

Workup

  1. customThe reaction mixture was equipped with a Dean Stark trap
  2. additioncontaining 4.0 angstrom molecular sieves
  3. temperaturerefluxed for 16 h
  4. customThe reaction was transferred to a separatory funnel
  5. additioncontaining
  6. extractionextracted with EtOAc (3×100 mL)
  7. washThe combined organics were washed with H2O, brine
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated
  10. customThe resulting oil was purified by column chromatography

Sources & evidence

ORD record
ord-c3f727e60ba94b58b4a8471646112129
Source dataset
uspto-grants-2007_06
Patent number
USRE039679E1

Reaction notes

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