Ethylene Glycol → 2-(4-Bromothiophen-2-yl)-1,3-dioxolane

HRID 458413Notes

Reaction equation

HRID 458413 reaction equation
C1C=CC=CC=1.[Br:7][C:8]1[CH:9]=[C:10]([CH:13]=[O:14])[S:11][CH:12]=1.[CH2:15](O)[CH2:16][OH:17].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CCOCC.O>[Br:7][C:8]1[CH:9]=[C:10]([CH:13]2[O:17][CH2:16][CH2:15][O:14]2)[S:11][CH:12]=1

Participants

7

Reactant 4

HCID 174Ethylene GlycolHCID 241BenzeneHCID 877924-Bromothiophene-2-carbaldehydeHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 38572552-(4-Bromothiophen-2-yl)-1,3-dioxolaneYield 90%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

A benzene (55 mL) solution of 4-bromo-2-thiophene carboxaldehyde (9.76 g 51.09 mmol), ethylene glycol (8.55 mL, 153.26 mmol) and p-toluenesulfonic acid monohydrate (0.972 g, 5.11 mmol) was refluxed with azeotropic removal of H2O for 6 h and then cooled to ambient temperature. The reaction mixture was diluted with Et2O and the organics washed with sat'd NaHCO3, brine and then dried (MgSO4), filtered and concentrated. Chromatography on silica gel using 95:5 Hexanes:EtOAc eluted the product to provide the title compound upon concentration as a yellow oil (10.76 g 90% yield): 1H NMR (CDCl3, 400 MHz) δ 7.22 (s, 1H), 7.08 (s, 1H), 6.07 (s, 1H), 4.14–4.00 (m, 4H).

Workup

  1. washthe organics washed with sat'd NaHCO3, brine
  2. dry with materialdried (MgSO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. washChromatography on silica gel using 95:5 Hexanes:EtOAc eluted the product

Sources & evidence

ORD record
ord-b38d458893a746409b3db3f851fa7406
Source dataset
uspto-grants-2007_03
Patent number
US07189851B2

Reaction notes

Loading…